One option to increase the amount of battle levels for bash 13 is to convert 'quality' TSF battle levels to 1.23. One pack in particular I have my eyes on is street wars. If someone could convert those levels (shadow? permission needed?) to 1.23 that'd be great. The townhouse tilesets are simply too big to work in 1.23, but there are 1.23 versions of them.

If there are other decent levels which can be converted, but have tilesets that are too big, please convert them (assuming you have permission and there are 1.23 versions of the sets).