If you go to the Alembic Store, they offer a bag that fits the Series I/II large body basses. My Series I 4 string Omega body, which measures 49 tip-to-tip, fits in most standard size bags and in a double bag that I have if I need to carry two basses. It only fits in that bag if it is in the back position, with a shorter bass in the front position.
I also have the prototype for the bag that's sold at the Alembic Store. It fits my Series II 5 string Point Body (51 tip-to-tip) with room to spare. I had bought a used Reunion Blues bag from a guy who swore it would fit a 51 bass. One day I'll post a picture of what that looked like. When I discussed it with him, he was more than willing to take it back for a refund, or make me a custom bag to the dimensions of my bass. He was partnered with a guy who used to work at Reunion Blues, so I agreed to let him make me the bag. After I got the bag I suggested he get in touch with Mica. Actually, now that I think of it, there may be a thread somewhere around here about that.
Peace,
James