It just dawned on me that if you take out the NS-37, and replace it with the ShVAK, adjust the fuel tank volumes a bit, you have changed a Yak-9T to a Yak-9M, which was just an updated version of the Yak-9D.
And, if I'm not mistaken, more -9Ms were produced than -9Ds.
[ 08-14-2001: Message edited by: leonid ]