Fzr Sumitomo 4 pot calipers-how to recognize

I have sumitomo 4 pot front brake calipers on an early 88 fzr400. Do the stamped numbers help identify the caliper? Ordering new seals and maybe pistons.

 

FZr's didn't have 4 piston calipers until 90 model. Picture of the other side of caliper would be helpful, is it smooth?

 

more pics below. The front end must be from a later 400 or 600 if 4 pots were fitted?. i was hoping maybe sumitomo's had markings that might confirm the piston size or indicate which bike they were from. While were at it, the gold rear caliper is likely stock?. Thanks

 

They could be standard 90 FZR400 calipers.

 

The rear caliper is stock 400.

The caliper that is apart looks to have even size pistons, so thats the 400/600/early 1000 style. The caliper still assembled looks to have a smaller leading piston which is more like a later model 1000 part, but still a bolt on.