For those of you still utilizing trusts for NFA stuff you will need to submit (2) fingerprint cards for EACH person on the trust. I'm definitely not an expert, but I'm getting ready to submit for some stamps and found this guide that was helpful: http://www.ar15.com/forums/t_6_17/465636_Work-In-Progress--new-F1-F4-guide-for-41F-submissions.html
The big issue for me is I have 3 people on my trust, so I have to submit a total of 6 cards for each stamp. While at the SAR show I got a stack of fingerprint cards from the ATF table. I asked one of their representatives if the fingerprinting had to be done by a state/federal agency or if it could be done by yourself or by a private company? The lady's response was that it did have to be done by either a state or federal agency. This is a well disputed topic, of which I don't care to argue about. Until a submission comes back as approved or denied using any method of fingerprinting (cards, digital, self administered etc.), we really won't know the answer. I agree that 41F doesn't specify what the agent said. I'm also aware that the weather affects what the ATF says on any given day. I'm just the messenger.
Either way, I was looking up places to have the fingerprints done and most private companies charge anywhere from $15 per card all the way up to $65. I called my local police station and a few others and they didn't provide printing services. I found the City of Phoenix Police Department Code Enforcement Unit at 1717 E Grant St., Ste 100, Phoenix, AZ 85034 and they do printing for $6 per card. I was just down there and the process was really simple and quick. Fill your cards out before you get there, check in at the window, wait for them to call you back. Easy.
Hope this helps.