The Hispano Aviacion HA 1109 - 1112?s also have asymmetrical fins, as they are Bf 109 licence built airframes. However when the Spanish could not get DB engines, they used Hispano-Suiza engines, rotating the other way round (left) as DB?s and Merlins (right). So the flat and the curved side of the fin changed sides with the batch equipped with HS engines (compared to the original 109?s, and the later batch equipped with Merlins from the start).
However, when the original HS engines were refitted with Merlins in (at least part of) the first production lot, the Spanish did not change the fin. So these planes had the "wrong" fin, or at least the wrong side curved, adding to the torque effect. Those beasties were even nastier to handle during start and landing than the usual fishy handling of the 109.
The first airframe of Messerschmitt Stiftungs G-6 D-FMBB (not the current!) was such a composite, starting with Hispano-Suiza > RR Merlin > DB 605 (in fact a Volvo licence one :wink: ). It was crashed during start around a year after maiden, beeing a 100% loss. No harm to the pilot though, the engine went into the 2. airframe, the current G-6 D-FMBB.
Other ones known to have (had) the "wrong" fin are OFMC`s G-BOML, and Air Fighter Academy`s D-FMVS (formerly with Harold Kindsvater), (both Buchons HS > RR engines) and the currently rebuilt Fighter Factory`s G-4 at MeierMotors, when it still was a Buchon (the new fuselage got a different fin, correct for the DB 605 it will receive).

So the fishy handling qualities of some Buchons or 109s using Buchon airframes is not necessarily a fault of the original design by Willy Messerschmitt, but the result of using a fin that added to the torque instead of diminishing it. Of couse this is only true for the a/c originally built with Hispano engines, and later refitted with Merlins (and DB?s), not for the ones that got RR`s when they were built (those got the correct fin for the right hand turning RR?s, HA did know what they were doing!). Maybe the Spanish Air Force should have refitted the fins as well when changing from HS to RR, but they might have thought it to be unnecessary or just too expensive. And at least they knew.

I bet, initially some or most of the private owners did not.

Taken from here - http://warbirdinformationexchange.org/phpBB3/viewtopic.php?f=3&t=50082

I never new about this, is this also replicated in the sim ??