There is no AG List, never has been and never will be!
The EOPS List is only the first step wrt dealers transferring handguns in MA. Almost (if not all) Glocks are on that list. The AG had a hard-on for Glock and killed their ability to sell new Glocks in MA except to active LEOs.
Check with MA dealers (give model and S/N) and if they will transfer it. If so, and that is what you want to do, just do it and don't advertise the fact (only the dealer can get in trouble, not the new owner).
As for loaning it, Fed Law states that loaning handguns across state lines can only be done for "sporting purposes". We don't really know exactly what it means, but if it is left behind for the person to use for self-defense in any way, there is that possibility of the Feds prosecuting both parties. It's a gray area at best.