Technical Wheel cylinders…

Trying to find some replacement wheel cylinders for my 1940 Oldsmobile series 60. One pair is stamped: EIS 520 EW 6092, and the other pair: EIS 521.
I tried looking them up online by the number, and by the car and model. I had a few hits on EBay but no interchange lists. Lots of the wheel cylinders look similar and I’m installing an F100 dual master cylinder. I guess I could make a pattern out the mount bolt pattern and bring it to the local NAPA…
Any suggestions would be appreciated.

 

https://www.fusickautomotiveproducts.com/departments.asp?dept=130

 

Can you clean them up, replace the rubber parts, and use them?

 

I met a guy at Pleasanton during a GG swap meet. His name was Joe Way (sp) and he sleeved wheel cylinders and master cylinders in SS.
There’s probably others that do as well (assuming yours are pitted).

 

This place has 2 of the 521 wheel cylinders.
https://instockmotorsports.com/eis-521-wheel-cylinder-assembly-nos/

 

Thanks for the info, I will see about ordering some soon…