I might have the Olive oxford left. What size are you looking for? Also it happens to be part of their stock program and should be available all the time. Currently it is out of stock with them (I tried to order one for myself the other day) but they will be getting it back in stock at some point.
Really depends on the season/material/color (which is absurd imo).
Purchased a blue OCBD from two seasons past in XS that was perfect.
Same in white couldn't even be fully buttoned.
I will second that some shirts do fit a little bit different based on material and season even though I am sure they all start as the same body. Vintage shirts are washed in the factory so that is probably the source of the variation.