I just got through building a pin press, but it was a waste of my time. It doesn't come close to giving enough pressure to "smash/squeeze/expand" the pins. I only used a six ton bottle jack. I probably should have gone with a much bigger one. The other problem I found with it is I can't keep the pin vertical under the press. It just wants to squeeze it outwards and slip off the pins.
I have always had good luck with using a hammer and small anvil. The only reason I wanted to try the press was because I sometimes get "ballooning" on the face and back of my bolsters (I typically only go with 1/2" width bolsters, which is kind of narrow) when I don't strike right on target.
My method is this: I don't ream the bolsters. I apply JB Weld the the knife (keeping away from holes) and attach my bolsters. The JB is just a sealant and a good indicator of how tight you are getting your bolsters to the tang. I have found that when I thought they were tight, I put a few more hits on it and more JB sqeezes out. I also use small vise grips to pinch the top and bottom of the bolster material while peening to get them as tight as I can to the tang.
I made a small hardened plate with I think 1/4" demples in it to start the peening process of my pins. This allows the top and bottom side of the pins to start mushrooming at the same time. I lightly do this alternating sides. Once the pins are mushroomed the same on both sides, I use the vise grips to pinch the bolsters tight and start peening and keep alternating the sides. Once I feel they are tight to the tang, I then use a small handled 2lb "sledge" and hit the bolsters flat on the anvil to really smash them in (pins). When I am done, The pins are pretty much mushroomed to nothing, just flakes of metal.
This works great for me. But like I said, I just run in to the faces "ballooning" sometimes if I slip up just a little.