Nice find, it looks almost new! In general clutch motors run at 3600 rpm or 1700 rpm (round figures), based on my experience I wouldn't mess around, replace the clutch with a servo, you won't regret it.
At the risk of being repetitive read this -
I'll repeat what Wiz and Dwight said, a 441 clone will best suit your needs and with the addition of the aforementioned plate and a table attachment you'll have one machine that will do what you want.
Hmm, doesn't look like any putty/glazing knife that I've ever seen, they generally have a little bit of flexibility in them. I'd go with it being a "general purpose" leatherwork knife. Definitely worth restoring.
I agree with kgg about electronics and sewing machines, the only electronics on mine are the servos. They tend to be pretty reliable but they are simple and relatively inexpensive to replace.
And yes, that's not the type of machine you need.
I couldn't find much info on that machine but looking at the photos it appears to be a domestic machine. If it is the one I'm looking at then I doubt it will be any good for holsters.
I see you've been giving the 3D printer a real workout, kgg! (That table for the Chinese patcher looks very nice).
Maint1517, which Pfaff are you looking at, given that you want to do holsters?
Essentially the same machine. Which one you buy will depend on things like the price, availability, and what extras they come with (or if you even need the extras).
Good idea with the magnets, it never occurred to me to use them like that. I have several that I've removed from old hard drives that should work (hard drives are a great source for very strong magnets).
The worn paint suggests a lot of use. Not necessarily a bad thing as long as it has been well maintained. Your requirements for the machine were fine - until you mentioned knife sheaths, it's not designed for that.
What Constabulary forgot to mention is it's an SV machine and manuals don't exist for them. Many Singer models had SV versions in their range, the best you can do is try and match it to a standard model and use that manual.
I wouldn't overthink it. What I noticed on a couple of carving videos I watched was the way the carver held the maul, if he wanted to give the stamp a decent whack he held the maul's handle at the end, if he wanted to have more control to give gentle taps he shifted his hand to hold the forward part of the handle and also wrapped his fingers around the head of the maul. This effectively shifts the balance point.
Which is precisely why we have that excellent sticky by Wiz about what machine(s) you need to sew leather. Even with that, the learning curve for a novice (me) was pretty steep.
Honestly, if you go into a dealer and say you want something to sew leather if they know anything at all about the subject they should not be recommending a domestic machine (of any kind). There is a very high probability that it will eventually end in frustration (or crying, if you're a gentle soul).
If it's an old cast iron machine there's a pretty good chance it will sew leather of some sort. How thick will depend on the type of machine. I have an old 201K, and while I didn't try sewing with it I used it for pre-punching veg prior to handstitching.