[Leica] Dr. Yao jotted down the following:

["Pfile, Jerome R" <jerome.pfile@eds.com>]

But don't forget in reality there are more than 3,130 'HM' cameras in
circulation: many of the classic 0.72 have been modified to become classic
HM by changing the rangefinder and top cover (the HM has 0.85 marked on the
VF window).  Also, Leica never published a serial number list
differentiating the 0.85 from the 0.72 cameras.

When I wanted to add a couple more classic HM to my collection to USE, I
found out the model had been discontinued.  My solution: I bought a pair of
used classic 0.72 and had the 0.85 top cover and rangefinder fitted.

If one were to buy a used classic HM I would make sure it comes with the
warranty card to confirm its authenticity.

Rgds,

Joseph

The "classic" M6 HM enjoyed not only a relatively small production life of
3,000 and change, but also a relatively short production life of 6 months or
so.  It came on the scene with relatively little fanfare, and certainly no
forewarning of a major (for Leica) design change.  As such I suspect very
few were "hid away" in the collector vaults before only the TTL was
available.  It would make sense that the bulk of HM purchases were based on
"using" the HM VF for its inherent usefulness.

While Doc Yao is correct that any classic .72 can still today be converted
to .85, it would be difficult to find one with clean warranty card and all
the packing with the labeled box.

Down the road 5 years or so away, my suspicion is that a "New In Box", never
registered, never used, .85 HM with all packing and paperwork, will draw a
significant premium over a .72 classic with the same papers.  There just
aren't many that fit that criteria.

Jerry Pfile