I had to fly into Boston a few times to exhibit at the Vintage Cup while it was there in 2012/13 and used a very helpful firm to clear my guns through customs.
Their details are
John Murray
Office Manager
J.F. Moran Co. Boston
160 Second Street
Chelsea, MA 02150
Direct line 617-409-0675
Fx # 617-889-6897
They were very efficient and reasonably priced from my experience of flying into the USA 3 times per year.
However, I am not a US citizen so can't advise if you really need to use a broker.
My advice is to do so if there is any doubt, with customs I have learnt that a payment up front can avoid serious costs after the event.
Your decision.
If you choose to fly into JFK the broker to use is
Mike Rea
Immediate Customs Service
jfkics@aol.com

Last edited by Toby Barclay; 05/02/16 03:49 PM.