Hi

With regard to contacting the B-25 builder, we do not give out email addresses. However if you want to write an email for him, I can forward it on - use my email address [email protected]

With regard to propellers, I understand the problems. APC do a good range of propellers, however all the ones that are suitable for our SP series engines are schimitar shape, which is not always what you want for scale. I did approach Master Airscrew at one point, however nothing ever came of this.
Other manufacturers which may be of use are graupner, bolly and (for wooden propellers) zinger.

I hope this helps.
Best regards
Laurenne