I could be wrong but the distant memory bank tells me that although Alan Shepherd was offered MV's for the 64 TT he could not get his oil contract changed to suit both MZ and his UK sponsor. Sorry I would have to look this one up in my old volumes of "Motor Cycle" to be exact, but I seem to recall this being the issue.
Incidentally Alan Shephed, who was in my opinion, one of the finest riders to race the TT, worked for the family firm,Allan Jefferies Motor Cycles for a while in 1956/57. I can just remember him arriving for work on his Gold Star with it in racing trim, and leaning it against the wall outside the workshop as it had no stand. I would then whiff the sweet aroma of Castrol R for a moment or two.Ah pleasant memories.
Sadly I understand that Alan is in very poor shape presently, as the result of a stroke. I do not know the exact sitation, but it doesn't sound very promising. Anyone out there who does know?