OK the Signature type.. ? Not sure..... I'm originally from NYC and surrounding area. Serotta is a popular bike there and everywhere. Shops that had not only Ser. but other bikes offered the Serotta fit kit. I don't recall the exact price but as of 2 years ago it was nowhere NEAR 375; often times I'd heard of places that would credit at least some of the cost towards a purchase. other types/ brands of custom fit procedures are out there, thats all I know. I'd look around. 375 seems hefty. My guy here does it for free, not Serotta but it takes a trip ror so, each time he spends close to an hour if needed.