06 Yakuza sohon bucho info

Hi all, I just recently got an 06 yakuza sohon bucho. Everything I have read about this frame tells me that it has an 83mm BB, but when I got the frame I measured the BB out to 73mm. The frame also does not have welded on ISCG tabs, so my question is do do I need some kind of spacers and ISCG mounting plate to run a 83m BB and crank? Or can I run a 73mm BB w/ an ISCG mounting plate? Sorry for the strange question I never had a frame w/o built in ISCG tabs. Also does anyone know the chain line for this bike and what the rear wheel is supposed to dished to? Thanks.

-D.K.-