A socket and a spanner wrench are both available at Numrich, although you may have to have an American buy them and forward them to you, since anything Boys is considered a destructive device in the US.
http://www.gunpartscorp.com/Manufact...tm?results=All
Allegheny Arsenals also has the same items, but for a bit more $$:
https://mg34.com/product-category/bo...ti-tank-rifle/