W123 Brake Master Cylinder: Bendix no longer available from MB. Swap to ATE?

[Screwdriver]

Greetings,

Lately, my brake pedals been sporadically disappearing into the floor panel after a recent copper hose + fluid change.

I thought about changing my master cylinder and called MB UK to order a replacement only to learn that they only stock ATE and no Bendix. I'm not sure what my next steps should be and have the following questions:

1) Can the Master cylinder be swapped in a straightforward manner? Bendix with an ATE BMC?

2) If not, what options are left for Bendix master cylinders? I'm guessing rebuild kits are available?

Thanks