Awwww a thread about me, I'm touched. But really that 1st pic you posted is amazing. It doesn't look like it's a real pic, but I really like the style of the drawing. It might be the best B25 drawing I've seen, where'd you find it?
I wouldn't worry about getting the P-51 in there though. If you do I would be very impressed, but I don't see a way to do it and have it look nice.
There are only two things I can think of to improve that sig, and that would be to remove the white border (doesn't look bad or anything really, I'm just not keen on it), and maybe make the text a tiny little bit smaller so it isn't coming off the edge of pic?
Yeah, I'm a picky one, I know, that's why I usually do the sigs myself. But you've really done an awesome job here, but it would be great if you wouldn't mind making a couple of small adjustments?
Great work though, thanks a lot!