Another search has revealed that there were actually three versions.
1) The version in my link (marked in degrees)
2) A version marked in the standard NATO mill system (6400 mils)
and finally
3) An Iraqi version from the 1970s and 1980s marked in the Russian mil system (6000 mils)
Apparently Iraq was still using British compasses but need them set up to use with their Soviet artillery. I can't get the link to work; I'll try to copy and paste the article. Sorry, I got the article but the pix won't post:
An Interestin M-73 Compass Variant
Posted on April 1, 2014 by Dick
What follows will appeal to few other than committed compass junkies, but I would like think there’s a few of you out there, so here goes.
The Francis Barker M-73 prismatic compass, made in the U.K., (shown below), is one of those rare things that lives up to its own press: the finest hand-held military compass in the world. It’s heavy and it’s expensive, but in terms of quality, accuracy, precision, and overall utility, they don’t come any better.
Standard M-73 Compass
The M-73 is available from its manufacturer, Psyer-SGI, graduated in either degrees or mils, but there was yet another version made decades ago that holds special historic interest. (At least to we aforementioned compass junkies.)
After the Allied defeat of the Ottoman Empire in World War I, Iraq, then known as Mesopotamia, became a British mandate and remained so until 1932. From 1932 until long after World War II, the United Kingdom was a powerful military influence and presence in the country.
The British Army adopted what was then called the Mark III prismatic marching compass in the 1930s. In nearly all respects, it is virtually indistinguishable from the present-day M-73, which remains a paramount example of the principle, “If it’s not busted, don’t fix it.”
In 1972, Iraqi dictator Saddam Hussein signed a 15-year treaty with the Soviet Union. As a result, the Iraqi military began making extensive use of Soviet weapons and weapons systems, including artillery and tanks and adopted, as a matter of logical course, the Soviet mil system, which utilized a 6,000-mil circle instead of the 6,400-mil circle used by the U.S. and the other NATO countries.
Sadaam may have used Soviet arms, but the Iraqis used British compasses. Ordered and issued were M-73s identical to their western counterparts except for markings and a 6,000-mil compass card. A good many of them have found their way here the hands of returning American service men and women.
Below are the dials of three M-73 compasses, all indicating north. At left is a degrees model with the dial showing north at 360 degrees. At center is an M-73 graduated in U.S./NATO mils with north – 6400 mils – indicated. The M-73 at right is an Iraqi, with north set at 6,000.
All Three Dials
The quickest way to tell the difference between a “western” M-73 and an Iraqi is by examining the base. Immediately below is a standard M-73; beneath that is an Iraqi model.
Standard M-73 Base
Iraqi M-73 Compass BaseThough an Iraqi M-73 is a desirable collector’s piece, it is also readily functional with the application of a little math. To convert Russian mills to degrees, multiply the mils reading by .06. Conversely, to convert degrees to Russian mils, multiply the degrees by 16.666 (or 16.7, for rounded-off simplicity’s sake).
Every so often one of the Iraqi prismatics surfaces on eBay, but it never seems to be at a time when I can afford it. Oh, well. Perhaps one of these days…
. Is the foam uncut ? Do you have pictures by any chance?
