The fact that I was working from Andy's plans, but without his castings and with the dimensions of what I had on hand created some problems. I bored the center of the body out to what I thought was the final diameter, then bored top to bottom to accept the bushings and vertical shaft (I scavenged the vertical stainless shaft from a junk sump pump impeller shaft, but bought the bushings from MSC for less than $5 each and could pick up the same day). I turned a brass cap to hold the bushing in place, lined everything up and drilled and counterbored it and tapped the holes in the top of the main body and attached.
Unfortunately, I hadn't accounted for the travel of the yoke inside of the chamber as the as the vertical shaft moved through its stroke. So back to the lathe. I made a stainless boring bar out of 1" round stock I had laying around and a cutter from .5" tool steel (thanks for the advice mikey and Pontiac 428!), and opened the circumference up another .375 to accomodate the yoke travel. Then I turned a front cap for the body out of scrap cold roll round, chucked it up on the rotary table and drilled and counterbored the cap, and drilled and tapped the body for 8-32 screws. The vertical shaft was end drilled to .250 and then half of the circumference was milled off except for 3/16 for the file to slide into. I turned a "top hat" to slide over the file and vertical shaft, and tapped it for a set screw to hold the file in place on the shaft (per Andy's prints). Then I sized, drilled and counterbored the base, and drilled and tapped the body for 3/8-16.
Next I put a slice if 7" round in the rotary table and began milling away the clearance areas and bosses for the table legs. Then I cut the legs, and mocked up the body and table to the legs so I could rotate the shaft and check clearances. I found that I needed to drill about a 3/4" clearance hole in the base, and mill additional clearance in the bottom of the table to accommodate the stroke.
I also drilled and counterbored the legs (added a third leg in the back of the table), and drilled the body and the bosses in the table and tapped to 3/8-16. I found that I had to use a half round endmill to cut access grooves in the bottom and sides of the table to access the leg bolts. Then I chucked the table into the lathe and faced the table top and circumference before bolting it together.
I wasn't able to use either of the two old motors I had laying around (the windings were shot). I ordered one from Amazon and had it in three days, along with a 2" pulley. I got some 3/8-16 brass inserts from ACE for the wood base, and drilled and counterbored the filer base before lining up and fastening everything down.