I can't recall ever having seen an SKB Model 100 (the basic extractor gun) as a Mitsui import, although I have seen 200's--and they were the least expensive sxs with automatic ejectors.

SKB's numbered 500 and up were all OU's, to my knowledge. And I don't believe there were "field" versions of the 700 and 800; rather, just target models (trap and skeet). The only straight grip OU of the original Ithaca SKB imports was the 680.