I ended up removing the inner 1/2 inch circular deflection coil stop. Had to cut it flush to the inside surface. This allowed enough space for the deflection coil to slide through and seat all the way against the crt neck. I drilled a hole 3-7/8 inches inward on each side from the covers' rear. The holes were kept along the same horizontal plan as the existing slots for yoke adjustment. I cut some 1/4 inch thick plastic spacers to fill the gap between inside housing and deflection coil clamp bracket. The trickiest part was placing a washer and nut on the inside end of each adjusting screw. I didn't want to drop them in the yoke or crt housing.
Two of the pictures below show the longer bolts I installed to extend the plastic housing rearward about 2 inches. I used 1/4 inch thick plastic sleeves as spacers over the four 1/4-20 hex head bolts. The upper two bolts are 4 1/2 inches long and the lower two are 4 inches long. The shorter bottom are to leave more clearance for the chassis.
These modifications made it possible to get the convergence coil assembly in the correct location on the crt neck.
I have yet to deal with purity and degaussing the screen, it's really bad. I also have to get the chroma circuits going yet. There seems to be no color, I'll try a new crystal before I get carried away.
Ed