I just finished assembling three pens and they look like crap, at least to me. I turned down as close to the bushing but when assembled, there is a lot of material above the parts. These are WC Slimline pens and acrylic blanks. I got a PSI catalogue and saw the catalogue had a set of mandrels, P/N PKMBCM2. Are they worth it? I have considered TBC and looked at the 60 degree live center at a couple of places. Recommendations for headstock and tailstock for TBC? I need to move up a couple of steps in quality as I am picky. I have a three piece set of calipers and a dial caliper so measuring diameter isn't an issue.