ms65 crown brake master swap info

[cresslux]

Hi Guys,

A while ago i got a '74 MS65 crown with a dead 4m + w40 and did a 5m-ge + w50 swap. car drives great and has given me zero issues until the brakes decided they didn't want to work anymore.
pedal intermittantly goes to the floor with zero resistance (I will admit a little bit of poo came out when it happened on my way home!). I am overhauling the entire system as god knows when it was last looked at but i am having trouble sourcing a new brake master.
I have had one place refund me when they nwere unable to supply, another still looking and if all fails i'll have it rebuilt but i was wondering if there is a master cylinder than can easily bolt in it's palce from another car?

any help would be great, google has not turned up much info.

[cresslux]

I ended up getting the master rebuilt with a stainless sleeve insert, happy days!