I'm under the impression that the OG chrome toaster centurions from Razor were supposed to be human constructed models, from that generation - they would have been the advanced production versions of the oversized prototype battle robot frame from Caprica. With martial, regal styling to denote them as formally part of a (human controlled) Cylon armed forces.
Likewise, the original "pie plate" basestars seem like they were the original human designed Cylon carrier ships. The tri-star basestar we saw take on Osiris in Blood & Chrome is likely one of the first Cylon-designed ships.
i'm right there with ya. i always felt like old school basestars and raiders were constructed by one of the colonies - probably to fight another colony - and then appropriated by the cylons.
as for the centurions we see in razor... it's essentially the U-87 from caprica
with chrome armor. think it's pretty safe to assume they are the human-created generation before the cylon-created generation of cylons.
there's a line in the script i have for blood & chrome
(which is an early version given to casting companies here in LA) in which beka kelly talks about her work for the cylons. i don't have it on me but she says something along the lines of "i worked on cylons, before the cylons started making cylons."
the script also features "stealth" cylons which have the ability to disappear or at least blend into their surroundings. i always thought it was stupid so i was glad to see it didn't make it into the final version.