I see one for sale now in Canada, a.270 with the brown stock and 6 (!!)extra magazines...(Those .270 mags fit 30-06 as well.) The mags are relatively expensive, so its a real premium to buy a rifle with extra mags.

I am a bit unclear on the three (?) different "Professional" models.

Firstly, and not to be confused with the three different models...I know there are the three different stock colors. An on-line British hunting site claims that the brown stocks were the first produced (late 70's), then the black and green ones in the 80's, and also that green is the least common stock color. (However, in my experience, in Canada, green is the most commonly seen for sale by far, then brown, with black being the rarest.)

I see in a S-M sales brochure from the 80's that the Pro was available with parkerized barrels in .270 and 30-06 but was also available in any other standard Model M caliber with the standard blued barrel. I have seen Pros in 9.3x62 and 6.5x55 for sale at gunshows in Canada.

Does anyone know the actual timeline for the three (?) Model M Professional models... including the ones without open sights (the MII?) and the reason for the simpler machining of the receiver on the MIII...(possibly a late production cost-cutting measure?)...see attached pictures...the bottom photo is the MIII)