I'm overlaying with those photos on top of each other in GIMP. I can line up the pickup screws, in which case the neck pocket routing is different, or I can overlay the neck pocket shapes and the pickup positions are different. And yes, the pickguard screws are different too.
Could one of those guards be for a Sterling by Music Man or OLP? I would not expect them to fit right (and they are not intended to). Or very different age EBMMs (like one is from the 1990s)?
HSS (Seymour Duncan) is a Sterling pickguard. My understanding, per a conversation with Brian Xavier Martin, is that all of the cut files for Sterling were identical to EBMM. I have used SbMM/EBMM pickguards interchangeabley on multiple models without issue. Screw holes always lined up. I'm most curious about whether the HSS & SSS neck position is different. I actually routed a swimming pool on the subject guitar, so the actual area available for the pickup is slightly larger...
Dibart77 - these are both Silo Special guards.
DrKev - I guess I'll have to buy a blank one a rout the pup positions myself. Thanks for your knowledge and input.
Anyone need a BWB Silo Special SSS pickguard? Brand new, plastic still in place.
The SS pickguard changed at some point. When I replaced mine earlier this year, they sent me two blueprints and asked me which one I needed. I could only find one difference, and that was the depth on the cut around the bridge (i remember it was exactly 10mm deep - and the wrong one was a lot smaller). The screw holes could have been slightly off on each version as well. My SS is a 2015, requiring the 10mm bridge cut. I'd start there.
On second thought, one could be for the MM, and the other for the Sterling. I don't have my Sterling anymore, so I'm no help there.
I don't know about the SS, but the Albert Lee ones definitely changed at some point. I have an original Pinkburst and the hole locations are different than in later revisions.