Forest Gump's "box of chawclits" dictum applies here.  
Those old timers were of the "Make it do" generation, so there is no limit to their imagination - or ingenuity
as they modified a tool more to their liking or altered one for a different caliber.
(This will be a dynamic page as something new/odd is always turning up and I have now decided to list them.)
Many of these come from my archives taken from eBay in years past, and I have no further info on them.
A No. 6 in caliber 40-82.  Can you spot the "improvement"?  Note the brass insert on the bullet mould.
A No. 1 in caliber 38 S&W with the fixed chamber cut off.   I can't quite make out if it is threaded (if not, why
cut it off?).  Maybe better eyes than mine can make them out.  What makes this one REALLY interesting is
that it follows the pattern of that mystery third version No. 1 in 32 S&W L[ong].  Have we found the Smoking
Gun? (no pun intended).
OK, what do we have here?  At first blush it looks like an early No. 4 with the fixed chamber nicely ground
off.  But . . . note the lack of a recapping stud on the mould.  Either it was never there, or was equally ground
off in a professional manner (why?).  Note also the notch on the large rivet that holds the two handles
together.  Caliber unknown, but looks to be either 38-40 or 44-40.  Opposite side wasn't shown, but if it lacked
the "Ideal" stamping, it would be a good "Talcott" candidate.
The assumption was this No. 3 in 33 Win caliber.  All that was shown
was the caliber side.  I assumed the other side was OK and only
asked the seller about the die stamping.  I was told "95" and "320"
(die body and bullet seating stem).  I assumed (again) that she
misread the "98" (33 Win) as "95" as the stem number (320) was
correct.    I won the bid, and on receipt, opened the package - and
nearly had a stroke.
A No. 4 in caliber 44 S&W R[ussian] that comes more under the heading of "Butchery".  The tip of the fixed
chamber was cut off but not re-threaded for any die (not enough meat left).  Sprue-cutter and bullet-sizing
stem also missing at the time of acquisition.  Probably used just as a mould, as it was in pretty good shape, but
why cut the tool up this way?
Courtesy D. Ciaramitaro
The tool had been converted to a 38 Special diameter case/bullet.   A
workmanlike job, but from a collectors standpoint, the tool's value  
was destroyed.  The crowning touch is that the seller was right - the
die WAS stamped "95" - correct for the Special but the stem was a
"320" (correct for the 33 Win.).  When I took a closer look at the pic
I could make out the 95, but I was SO SURE it was a 98, that's what
I read.
I received a refund from an ethical seller who didn't realize the tool
was modified.
I now ask questions, which sometimes upsets the sellers who think I
am questioning their integrity, but that beats the hassle of sending
an item back and being out the postage.
A typical user-conversion to make the bullet seating adjustable by tapping and threading the tip of the fixed
chamber to take a threaded screw.  The electrical tape on the handles is another add-on in an attempt to
insulate the user's hands from the heat of bullet casting, as these tools acted like a heat sink.  Note the
missing bullet-sizing plunger, another modification that is fairly common with these types of improvements.
An interesting piece from many standpoints.  First it is a somewhat scarce plum-colored version of a No. 3
converted to a No.10.  (You sense that the next one off the production line was the 310.)  Second, it was
converted from a 38-40 to a 45 ACP with the addition of a sliding latch to hold the rimless case for priming,  
Third, it (luckily) had a temporary brass bushing inserted in the priming hole that took a 38 Special-sized
case.  (I was able to pull it out and restore it to a 45 ACP.)  Lastly, it had a bullet-seating die (45 ACP) with
a non-standard stem.
After handling and viewing these "improved" tools, you get the feeling that back in the '30s and '40s, almost
every Ideal reloader was also a machinist, or had a friend who was one.
No. 6s with modified moulds
Here's one that brings a tear to my eye.  It is
a rare 38-35 Stevens No. 6 with the
adjustable die reversed - the so-called "Left
Handed" version.  Some previous owner
rebored the mould to cast a massive 61
caliber slug.  He also removed the cartridge
extractor hook for reasons unknown.
I have run into more than a few that have
had their moulds rebored or cavities
otherwise "improved"  They range from a
point added to the bullet design (see below),
converted to a two-cavity version by cutting
a round ball or other smaller caliber
alongside or modified for a solid-based slug
like the above.
A totally abused/wrecked 50 Gov.  The extractor
claw tip and the sprue-cutter stop were broken off
and the tip of the bullet modified to cast a blunt
stub.  What the user thought he would gain from
this small addition to a 515 gr slug is beyond me.
Note the hole drilled in the upper left of the handle near the hinge.  The tool was originally destined to be a
No. 10 with the swinging hook priming device to hold a rimless case, but the "use-what-we have" approach
by Ideal changed it to a rimmed cartridge.
A No.  3 22 Savage altered to handle to something like a 219 wasp or Zipper.  The
bushings appear to be a force fit like the plum No. 3 hybrid 38-40/45 ACP shown below.
Courtesy D. Ciaramitaro
Courtsey D. Elliott
Courtesy D. Elliot
"I sure doesn't taste like a V-8", or more precisely, look like a No. 3 in caliber 38 Long -
the pointed bullet-sizing plunger is a give-away.  For reasons known only to God and
some previous owner, the mould was nicely ground off a scarce No. 8.  Somewhat
unusual in these cases as the "modifier" normally wasn't that careful and left the
tool looking "lumpy" on the hinge end.
Kissing cousin to the 33 Winchester tool above, although the reason for modifyng the first station is a bit
murkier.  There is no case extractor hook, so why it was bushed remains a mystery.  Perhaps the hook was
removed later on.