if it is an old Moto, french BB's are now available from Velo-Orange at fairly reasonable prices.
If you're adjusting chainline at the hub you don't need "room" for spacers, you need to swap them from one side of the axle to the other to move the cog relative to the dropouts. If there isn't room on the side you move them to, you just thread the cones, locknut and spacers a little further onto the axle. For example, if you want to move your cog left (inboard) 2 mm, you'll take a 2mm spacer off of the left side an install it on the right. If there isn't room on the right, you just thread the right cone a little further to the left, the left cone and locknut a little further left, and install the right-side spacer and locknut. You should have relatively equal amounts of axle sticking out of the locknut on both sides once you're done.
Redishing the wheel will probably have to follow. This can often be done on the bike quite easily by tightening the spokes on the appropriate side evenly.
Last edited by tashi; 11-20-10 at 09:54 PM.