IDitlt and AlexB,
I did some searching through past Stovebolt posts, using the
search the Site tool found in the left margin.
This
older conversation has a bunch of still useful part number and rebuilder info about the booster you are seeking.
I checked the links to resources in the last reply posted by member "Micksurfer" and found all but one (the 2nd link) are still good links. A couple are to actual folks/companies that still offer rebuilding services.
Hope this info may be of some help in getting your brake booster issues resolved.
Dan