Started as a 10" f/5 GSO.  Replaced steel tube with TSOptics GSO Replacement (3mm thickness) Replaced focuser with Feathertouch 3” r/p for threaded coma corrector connection.  Replaced spider with TSOptics Heavy Duty spider Replaced secondary with TSOptics 100mm secondary Replaced primary cell with Aurora Precision 10" EQ cell (with fan) Replaced primary mirror with AstroReflect 255mm f/4.5 telescope is about 32lbs... 40.5lbs with camera, EFW, EAF, OAG, guide camera, and Pegasus Astro powerbox. All said and done, I could have saved money just buying a 10" ONTC... but... I didn't, and I'm quite happy with the outcome. Only thing I may do down the road is replace the CF tube with a thicker one but for now it does not seem to be required. Threaded connection for coma corrector made immense improvements (reduced from 0.7 as RMS to below 5 as RMS) as imaging train held much more securely.