Civilian Mark XI question

To help me avoid making a costly purchase mistake, I re-read the excellent
refrence article by Thomas Koening and Greg Steer looking for what I can learn
about the Mark XI variant that was sold to the civilian market. I noted the
following paragraph "IWC also sold genuine civilian Mk 11 watches. Two batches
of 500 pieces each have been identified from 1973 and 1983 and are
easy to distinguish from the military ones by the 7-digit case-number stamped
on the case back."

My two questions:

1. Have any civilian watches with the charcateristic 7-didgit number stamped
inside the case back been identified as having been produced in other years,
other than 1973 and 1983?

2. Have any civilian Mark XI been noted that have have movement numbers from
earlier production and case numbers from later production? In military issued
watches I understand that this is possible because MOD watchmakers were not
always meticulous about re-attaching case backs to their original cases after
they performed maintenance on the wtaches.

For dating cases and movements I used
www.moeb.ch/dyIWC/DYIWCh5/DateYourIWConline.html

Dear Elias

Are you sure you read the article series from 2020 updating the older article?

The production date is vague and ambiguous. There is a production date of the
case, the production date of the movement and a third date is the date the
watches were sold.

With most of the numbered cases of the first series the exact date of sale is
not recorded, but it appears a portion have been sold in around 1967 and it
appears at least some were sold to the military.

Regards

Th. Koenig

Hello Thomas: Thanks for taking the time to reply. The picture case back of
watch i was considering is below. According to

www.moeb.ch/dyIWC/DYIWCh5/DateYourIWConline.html

This case back dates to 1964 -1966. Is this not earleir than mentioned in your
article?

The outsside of the case back has no military markings and appears unmoleted.
Aaccoring to web-site I mentioned above the movement dates to dates to 1956.
This is almost 10 years earlier than the case production date I posted above
and what casued me to post my original question and become concerned that I
could be making a costly purchase mistake of a supposed civilian Mk XI..

Having said the above, I am aware that for bona fide miliatry issued MK XI,
one can occasionally see a mismatch between case back date and mov't date
apparantly because MOD watchmakers were not meticulous during maintenance of a
group of watches resulting in case backs going on cases other than their
originals.

And of course now that IWC Schaffhausen refuses to prepare an unoffical
"Letter from the Musuem" or "Extract of the Ledger" as they had done for me in
the past, there is no way for me to verify the watch BEFORE I make a purchase.

This series of cases of which you show one is not 1964, but later. A 1956
movement does not really fit.

So it appears the watch is not all original. If you like provide the movement
No. and a goot pic of the movement. I know these movements very good. In case
you post a pic of the movement pls make sure the balance doesn't swing.

Regards

Thomas

Three more seller's photos.

The case ring doesn't seem to match the wear on the movement.

There is a manufacturing date of the case, the manufacturing date of the
motion and a 3rd date is the date the watches had been sold. I am conscious
that for bona fide miliatry issued MK XI, you can actually every so often see
a mismatch among case returned date and mov't date apparantly due to the fact
MOD watchmakers had been now no longer meticulous at some stage in protection
of a organization of watches.

Dear Elias,

the watch case and dial are o.k. for a Mk. 11. But as your pic of the movement
does show, it is a Cal. 89, but not Mk. 11 movement as it lacks a specific
technical feature typical for Mk. 11. That matches the fact it was not sold to
a customer known to have sold Mk. 11 (not military nor civilian ones).

So I recommend to stay away from this watch unless the price reflects the
facts given above.

Regards

Thomas

Hello Thomas, THANK YOU very much for expert opinion and helping me avoid a
costly purchase mistake. To summatize what we discussed, the case, dial and
hands appear cprrect for a civilian market MK XI, however the Cal 89 movement
is not a military model? Again, many thanks. Elias

The movement is not only not a military model, it is no Mk. 11 movement at
all!

Thomas

Hello Thomas:

All I can say is THANK YOU as the mov't certainly fooled me. What is this
movement please? Kind Regards, Elias