is there a form for this to withdrawl a pending form 4 or do I just need to write a note with the proposed trust name and serial number and email it to the same email you send the the request for transport? Will the ATF send my refund to the address listed on the application or can I include an address in my note. It was a single shot trust submittal that is over 320 days in waiting and I have since moved (a check to my old address with hopefully get forwarded) and lost intrest in the project.

Lost interest in the project?  A form 4 is for the transfer of an item.  Haven't you already paid for something?

Do you mean a form 1?

Yup. Bought and paid for a suppressor that's been sitting in my FFLs safe for 320+ days since I submitted my form 4. The rifle I purchased it for has been recgsmbered and now I no longer have a need for the suppressor I purchased. I found a guy who was looking for the exact model I bought so we struck a deal and my FFL is going to ship it to his FFL so he can submit his own form 4. My question is just how do I withdraw my pending form 4 and get my 200 bucks back.

If I'm understanding you correctly...
You have an NFA item at your in-state SOT, and you are currently awaiting transfer from the SOT to you on F4.

If so...
The dealer who submitted the F4 needs to contact NFA Branch and ask that it be withdrawn/cancelled. The dealer will receive the $200 refund.

As soon as it's cancelled, he can F3 (eForm 3) to the other guy's SOT.

pretty much.

I sent an signed .pdf request attachment to the ATF email address formally requesting the withdrawal of the Form 4. I included the Trust Name / Serial #, the Transferee (me / trust) name and address and the Transferors (my FFL) name and address.

I found out that my FFL and the one who he will be shipping the supressor to are actually in the same state. If they werent a couple  hundred miles apart we probably could have avoided the form 3 altogether but it doesnt work because of the distance even though its in the same state. I dont know if this makes any different or not.

Ill send my FFL a copy of the withdrawal request I sent the ATF so he can submit it if they wont accept it from me. I saw somewhere that they will withdraw on a phone call but I doubt it.

Thanks for all the help! All this work to simply possess a baffled tube of stainless steel is absolutely ridiculous! the same device is a requirement on my vehicle but putting one on a firearm takes an act of God and the patience of Job.