Pop,
A 637 Form is for Federal Excise Tax.
You can go to www.irs.gov and request form 637
There are a number of post here in the Docks with the title of, Federal Excise Tax on Fishing Tackle.
If I can be of any help please feel free to contact me.
Chuck Vanover
Tight Line Anglers Products
Ph. 440-277-1511
Fax 440-277-9152