This is my first post here, but I've been reading for a while and only just registered. I got fed up with not being able to read the attachments
I used this forum (and a little bit on Practical Machinist) in my research. This thread (and a few others) were instrumental in figuring out what I had or wanted. The first real vise I bought was sort of on a whim because I needed a vise for my new [to me] workshop. and I didn't realize what I found until I brought it home and read up on it, the history of the company, etc. Turns out, it's a C. Parker 974 in excellent condition (but it was missing the No. 2 wrench - more on that later.)
I went to a friend's grandfather's shop a couple nights ago knowing that he had a pile of old vises he wanted gone. There were 18 bench vises and 3 drill press vises. The drill press vises had been beaten, drilled into, and were all missing one jaw. It's sort of a shame, but I didn't take any of those home. I did take home a smaller Wilton torpedo style that's missing the back cap, a C. Parker 975 (5" wide jaws, opens 8", weighs 104, swivels), a C. Parker 994 'Big Bear' (4" wide jaws, opens 5", has anvil, weighs 89 lbs, very beefy), a small Columbian, and lastly a Simplex (mfg in Woonsocket circa 1941, a little smaller than my 974 Parker).
His grandfather purchased the shop in the 60's (maybe late 50's?) from a welding company that did work for nuclear plants. He told me some of the names of the plants that the shop helped build, but I was overwhelmed with all the old iron... To make a long story less verbose, he wants the space in the shop cleared out. I'm going to buy the remaining 13 bench vises, probably keep a few, and I'll post the rest for sale. There were mostly Parkers, a couple Simplexes, and a couple Columbians. IIRC there were at least 2 more 994's, there was a 674 1/2 (same as a 974 1/2, just made for sheet metal work), at least one 294, and several others. Some swivel, some don't. I felt like the guys from American Pickers digging through this stash... I don't plan on keeping all of them for myself, though. I want to give them all a new home where they will either get used or restored (both, perhaps?).
There were a few extra Parker No. 2 wrenches there too, so I grabbed one to put on my 974. To the owner and his grandson, these were all just old bench vises taking up space in their shop and it worked out in my favor when it came time to pay for them.
Here's the Simplex 41S (49lbs, made in Woonsocket) that I gave to my father. The ruler in the pictures is 16" long.
From L to R, C. Parker 994, C. Parker 975 (missing the anti-finger pinching device), C. Parker 974, Columbian with bent handle, Wilton. The 994 is going to my friend.
My 4
The Wilton got beat on

(it's also missing its back cap)
Little guys (that's a 24" ruler)
Same ruler next to the C. Parker 994. It weighs 89lbs.
5 minutes with my torch and hammer on the purple Columbian.
I'm going to buy the rest of them with the intent to keep a couple for myself and sell most of the others. I might go get them Saturday... We'll see.
I realized I didn't have one of the 975 next to the ruler... I'll be making a spring loaded brake thing for the handle too. A quick trip to the hardware store should do the trick.