If I was to get a 95(ish) SL60 but the AMG 3 piece split rims weren't on the car, is there anywhere that sells replicas or possibly second hand originals
Original AMG split rims crop up on eBay from time to time, but they're expensive and rarely the correct size. For the R129 SL, fronts should be 8.6J x 18 ET25 with 245/40 ZR18 and rears should be 10J x 18 ET25 with 275/35 ZR18.