I'll second the "Old Brown Glue" recommendation. I've used it only once, 
but thought it worked great. My only experience with hide glue in a glue 
pot was in a class from Roy Underhill, and I was not inspired to go 
through the fuss with it again. Downside for the Old Brown was the 
expense, especially because I used no more than a quarter of the (small) 
bottle and then didn't get back to it before it went bad.

--Chris

Check out H-frame, the site for vintage Black & Decker Workmates
<https://h-frame.weebly.com/>