Here is the original mini-story behind the Bf-109M series shown on the first page (and reproduced below):
"Following the success of Unternehmen Wacht am Rhein, and the sudden death of Stalin which halted the Soviet advance in the East, the German forces found themselves defending their own borders. Whilst the new jets/rockets were promising, the tried and tested Bf-109 and Fw-190 versions still formed the bulk of the Luftwaffe’s fighting force. In the case of the Fw-190 it was the Ta-152 series that now ruled. Alongside it was the new Bf-109M (“Martha”) series – the Bf-109M-2 being the first variant to enter wide-spread service.
The Marthas were perhaps the greatest change since the Bf-109F/G series were introduced. Based upon the Bf-109K, the M-2 was fitted with a DB-605L engine with a two-stage supercharger and MW-50 water-methanol injection giving just over 2000HP. This drove a new 6 bladed contra-rotating prop which not only gave greater thrust (speeds in excess of 725 km/hr (450 mph) were regularly attained), but also helped reduce the take-off/landing difficulties long associated with the Bf-109 series (a major aid given some of the inexperienced pilots now being pressed into service). Standard armament consisted of a single MK-108 30 mm Motorkanone firing through the propeller hub and twin MG-151/15 15 mm cowling guns. The greatest visible difference however was the new cut down rear decking/all round bubble canopy. Copying the ideas already seen in the similar late war Spitfire series, this was introduced at the request of pilots who argued that even the so-called “Galland Hood” of the late G/K series wasn’t sufficient. This new canopy was similar in basic design to that developed for the new Me-262 but was obviously smaller to match the contours of the smaller Bf-109. It also featured cockpit pressurization.
By the time the war ended in February 1946, over 1200 of the new Martha series had been produced."