I checked Yahoo and there are a couple of Gammill longarm groups there. You may want to join them and ask there. You need to create a Yahoo ID first, but it's free. Here are the groups I found:
https://groups.yahoo.com/neo/groups/GammillOwners/info
https://groups.yahoo.com/neo/groups/gammilllongarm/info
https://groups.yahoo.com/neo/groups/gammilllongarm/info (not very many members in this one)
There are quite a few Gammill owners on the homequiltingsystems group too (a large and active group)
Also check out the Gammill forum:
https://www.gammill.com/forum/