Difference between model numbers of the Samsung S2 Classic Watch

Does anyone know the difference between the model number, in terms of which replacement parts fit which watches? For example, I have a SM-R735V and I need to replace the back of the case. I found a back case plate for an SM-R735T model on EBay and the seller says it won't fit. I'm wondering, though... is that really true? The SM-R735V is the Verizon specific model, so the "V" in the model is probably that... and the software / branding may have nothing at all to do with the physical components of the watch... so an SM-R735 may be the same for all SM-R735xxx watches. Does anyone know how that works with this watch? Thank you in advance!