I noticed that in the photo at http://www.geocities.com/joelcrowservo/HofnerBass.html, the bridge on that Hofner is definitely angled to help with intonation...and a bit more than I've had to angle a floating bridge. That probably is some indication of the need for the later corrections to its intonation.
From what I read in that "Bass Player" interview I mentioned earlier, Macca stated that the Mandolin brothers found out that the stock placing of the frets was incorrect making it impossible to properly intonate the bass. the solution was to replace the fingerboard and re-fret the whole thing using the proper fret distances.
Ilan, did he mention any of that to you?
In addition, in my ten years of working as a repairman, I have worked on Hofners before and many of the sixties ones have necks that like to come off after a while. So I figure the neck re-set that the Mandolin Brothers performed was not so much a case of changing the neck angle towards the body, thus laying strings lower on the fretboard, but more out of necessity, since I know from working with old Hofners that they have the tendency to disassemble themselves over time, probably to the quality of the glues used.