Thanks to you both for the links.
I am quite interested in looking into making a portable hydraulic rivet press.
I'm no engineer, but it's much easier to manufacture something after you have already seen somebody else do it & kind of takes the hard work out if you can copy one that has evolved through the trial stages into an efficient tool.
I have a Ford chassis which has had 2 rear cross members removed for shortening but they never finished the job. Of course, at least one of the members has been misplaced or lost in transit as the truck moved through several previous owners.
Always a pain to undo this kind of vandalism, no matter how well intentioned, but despite this, the chassis is still worth saving. I don't want to see this poor old thing get scrapped if I can avoid it. The irony is that several months ago I arranged to meet a fellow at a farm where he was retrieving the front half of a Ford F60, but he didn't want to take the rear portion of chassis or rear axle. I bought the axle & wheels, after chassis was cut forward of the axle. Together we took the spring shackle pins out and I had the axle loaded onto my box trailer. He offered me the chassis at the time, but I declined due to space. The chassis had (possibly still has) the cross member that I am now wanting! It's about 2 hr from my place, and I have not been able to contact the farm owner to ask if I can still have chassis. I will keep trying as I know it is EXACTLY what I now need!
Rule of thumb: NEVER pass up offer of ANY parts if at all possible. You will no doubt need them at some stage.

to you both. Thanks again!