The Prontor and Vario #00 shutters I have are all identical spacing, one Prontor is pre-WWII the other and the Vario are post WWII with flash synch, I can't check the Compur as it's got all the gubbins for the parallax correction for a Super Ikonta on it.

Dan makes a good point about the Super Angulon being more critical on it's spacing, I know Dean Jones in Australia (RazzleDog) found that spacings varied on 90mm f6.8 Angulons and that this affected the sharpness. So if you can measure the original Compur you could shim if necessary.

Be aware that some of these #00 shutters have raised face plates and it's just possible may not allow a SA's front cell to screw in fully. (Have S1a service manual for you BTW).

Ian