It looks from pictures that the strap, where it meets the lug, it quite tightly fitted by virtue of what appears to be a curved strap and springbar.

Since I don't have one to play with, I was wondering if anyone could shed some light on this: because of this tight fit, does this mean that the springbar holes are placed very close to the edge of the case, thereby making it difficult to retrofit a normal, straight-end strap? So is one forced always to have dedicated Tresor straps for replacement?