OTS may be my 2nd build soon. I've noticed the newer kits come with all Metal Film resistors. I've seen older versions with more Carbon Comp's. I like carbon better, Is this something I can specify w Nik?

The brown, Dale-brand, metal-film resistors have been stock on the Ceriatones since they were introduced; and MF are easily the most commonly used resistor for ODS and Dumble-style amps, including the real deal (who used Dale as well). While Dumble started with carbon-comps, he migrated over time to carbon-film and MF and you'll find MF as stock in all the major ODS-style builders....Fuchs, Two-Rock, Quinn (Dale), etc. They are also stock in Dr. Z, Komet, Allen (Dale), etc.

CC's drift and are noisy and you don't want superfluous noise in any higher-gain design. If you want to use carbon, then use a tight tolerance carbon-film.  CC's are almost unique associated with old Fenders, Marshall changed to CF by their Plexi heyday.

Aside for all of that, CC'ss are more expensive than other resistors despite being of poorer quality than was was available 4 years ago. You can't get an "audio grade" CC like Allen Bradley anymore and the NOS often have moisture issues. I only use CC for vintage repair anymore.