You should be careful with the /U and /R packs, they aren't really true versions only optional addons either applied in the factory (/U) or as field-mod kits (/R) - and it is even possible to have multiple kits applied at the same time.
So you could have something like Me-109G-6/U2/R3/R6 (U2 - GM-1 boost, R3 - droptank installation, R6 - MG151/20 underwing gondolas).
Some of these options could warrant a new version, but others would be best dealt with as additional loadouts...
Add to the confusion, the numbering for the U and R modifications was different for each aircraft and many cases, different between production series i.e. Us and Rs on 109Fs varied compared to late model Gs. One of the things to consider with all these modifications is are they useful in this game? Admittedly I am guilty of this, but some aircraft only serve as visual variants ingame (e.g. the trop series) BUT there are many (say the 109 with bad weather equipment or the radar equiped versions) which serve little practical use ingame. Whilst more aircraft is always greater to have, simply having them for the sake of having them is not sufficient considering the work involved adding them to game.
But otherwise, thanks for compiling the list. It will definately serve as a good reference!
