I have no problem finding pdf scans of Owner's Manuals for typewriters thanks to the diligence of many people; however (with the exception of the WW2-era manual scanned and posted at Maritime.org) cannot seem to find ANY old service manuals -- the kind I envision being half-covered in machine oil and grease on the workshop benches at the Olivetti factory, the Hermes plant, the Groma gulag, etc.

The companies must have created some sort of professional repairman-level detailed maintenance / repair manuals for each of their many models I would think, but I certainly cannot find any online.  Anybody know anything more: where to find them online, buy them, etc.?

Like a Chilton's auto repair book but for typewriters.