With no disrespect to @CGT80
Looks like something that could be made with a straight push $40 De-Sta-Co clamp and a piece of angle iron (3"x3"?).
Some toggle type straight line clamps are rated up to 2500# !!
https://www.mscdirect.com/product/de...53010?fromRR=Y
There are others that would work too.
https://www.mscdirect.com/browse/tn/...vid=4287923274
It would not require any welding or machining other than drilling holes.
Something I'd attempt if I needed a dedicated sizing press.