I would look at U.H.M.W. - polyethylene. It doesn't glue well but can be bolted & screwed.
I have some scrap pieces around 1" to 1-1/2" thick. if you wanted to give it a try I could mail you some.
UPDATE!
I've been able to get a complete copy of the papper from the Manchester Association of Engineers http://www.mae.uk.com/.
It turns out the missing plate figures were on pull/fold out pages and the people who digitized them for Google musnt have had the time or equipment to properly scan them in.
Watch out for some of those "cheap" shipping companies. I've had one of them unband & depalletize items on me resulting in damage & uloading problems. They basically told me tough luck when I called them up about it.
A few week ago I picked up a 6" post vise and some large allen wrenches (over 1" hex). Also bought a neat stamp that stamps a 2" ruler scale and a brass ballpein hammer. I had some pictures but my camera card went belly up.
Do you have a place to mount a post vise? I have a few extra ones in the 4"-5" range and I could send you one if you think it would come in handy. screws and boxs probably have some wear. I'll try and get some pics next week.
I've heard of these sources but never used either:
http://hitnmiss.com/25a.html#pulley
http://www.paperpulleys.com/
And of course there is always ebay.
If you need belting and can use the composite rubber belting Tractor Supply stores are clearancing out their "by the foot" rubber baler belting. According to my local store the reason for the clearance sale is that they are going to pre-cut lengths only.
I don't see the big gain of this design over the standard tire hammer. Your adding extra parts and more mass (tire & large pulley) that the motor needs to get spinning to make the hammer move.
I find that prices on vises like this vary alot depending on who is selling & who is buying. If I found a vise that nice I'ld probably be willing to pay upwards of $200.
Nice! What system are you using for the ram slide?
Beaudry Champions had the solid spring arms with the rollers internal to the ram. The Beaudry Utility hammers use the coil springs & had the external rollers.
I don't think I could drive a 1" drift through 2" plate by myself. I would give it a try if I had some one to help me. I've been considering having some 2" plate waterjet cut or a striking anvil with the hole cut slightly undersize & file finish to size to clean up the kerf.
The 4340 steel showed up today! It arrived with a few gouges/nicks from the shipper but most are in areas that can be machined off. I got the big saw were I work to slice me off two 4-3/16" chunks and cut the rest in half to make it easier to move and fit in my truck.