1985 745t m46

I'm currently preparing to replace my front rotors and pads and have a question. Originally my 1985 came with 1 piece rotors (at least my reading appears to confirm this to be the case), but I believe they have since been converted to the later 2 piece style. In buying the new rotors I have been trying to make sure that they have, in fact, been converted, and am wondering if someone can confirm this given the below.

When looking at my existing rotors I can see they have smaller holes all around between the bolt holes (not just wher eteh guide pin is). The pictures I have seen of one piece units show they lack these holes, while the 2 piece systems do have them.

Are there single piece units with these smaller holes, or is this information enough to confirm a 2 piece system?

Both are 10.25" diameter, but the one and two piece systems I've seen have the same diameter so this doesn't help me. I've looked and there appear to be seams where the middle and bolts protrude through the rotor, but the 1 piece system I saw a picture of seems to have the "fakey" looking seams that could by misconstrued for a two piece unit...

Last note: the rotors have been replaced before... approximately 2 years ago or so. Would the mechanic and/or PO have converted them by default?

Any help is appreciated.

Thanks,
rt