So you need one of these. Twist the blunt side with some of the masking tape.
I'm sure you have seen how a saw "teeth: look like.
Use the "triangle" file from the set I have sent you and make these ( but small) "teeth" to the sharp edge of the razor-blade. Something like in the shot below ( the top edge).
I might have found you a suitable wheel to use as a tail wheel H, just need to check it against my 1/48th P47. If it's the right size, you can fit it to the kit's leg. Still only found one main gear leg though, but I'll send what I have, and try to get it in the mail tomorrow. Been a bit stiff to get to the Post Office since Saturday!