Hot Rods Please help me identify MCs

Im working on a 32 ford coupe with dual master cylinders.
Im trying to find rebuild kits, but I can't
make out the part numbers completely. also, it seems that the
bolt holes are an odd spacing (It seems).
Also, I don't see any online with circular extrusion on the sides
They are stamper FoMoCo

Specs:
Bore Diam 1"
Bore Depth (If I'm measuring correctly?) 4.5"
Horizontal mounting bolt distance center to center
Vertical mounting bolt distance center to center
Part numbers appear to start with AA 21???

 

My off the cuff guess is 55-ish Chevy.

 

Sorry, should have mentioned, They are stamper FoMoCo
I edited original post with that info.

 

1956 Ford.

 

57-60 Ford truck. They used a hydraulic clutch

 

In the '60's, every '57-60 F100 in the junkyards was missing the pedals and cylinders.

 

Educate me... a pair of MCs, one for front and back brakes or one for brakes and the other for clutch? Before dual MC s?

 

One is brake, the other is clutch.

 

If the bores are good and you get regular '52-'59 Ford car kits to rebuild them; remember to leave the residual valve out of the clutch m/c.

 

Thank you for that, I would have made that mistake.