I do remember the32nd Mustang, and have one of the 50th Ann. reissues of that one, the Phantom Mustang with clear fuselage and wings. You may still be able to find this one here and there.
The Revell 32nd P-40 has been reissued many times over the years and can still be found fairly easily. It may still be in the catalog, but I'm not 100% sure about that.
And evilBay is a good place to find old kits sometimes, but just be careful not to get too caught up in the bidding. Sometimes it gets outta hand! LOL
Also, what you just did, making this post and asking the question itself can sometimes garner a response. I have a few collectible boxings of the P-40's, but unfortunately I'm not looking to unload any at the moment.
Fade to Black...