was this resolved whit?
there are two bolt patterns on the 2tg(eu). early 2tg had a narrow spacing which looks like your bellhousing but there is a reduction starter found on later 13T-U too with narrow spacing. the 2tgeu/3tgte use a wider spacing so will not interchange to the early 2tg bell.
The reduction gear starter motor sits above rather than below the hole in the backing plate. Is yours upside down?