Correct mate.Series 1's were B,C and a few rare D plates IIRC.
I don't think it's a genuine series 1, I think it started out as something else. No s1 was Y reg. I could have been an rs1600i, but deffo not a genuine series 1 !
The gartrac conversion is mint (most on here won't know what gartrac did, nor who they are tbh)
It looks awful though.