jamesinc https://ozvolvo.org/discussion/comment/183117#Comment_183117
I doubt you'll find it on a B23E as it probably was a K-Jet motor, which had a different piece there for the WUR
Ah. Well, that figures why I can't find any cover from that engine, however I have a FP cover plate from the LPG B21, although it has a hole in it and is fitted with a brass bung. Looks like it was used for crankcase ventilation.
I also found these B21 / B23 timing cover bits, the plastic part is p/n 1266913.
Lemme know if you want 'em and I'll post 'em off tomorrow.