Our confirmed drawing has a locating shoulder. The delivered mounting plate looks different and its label has another suffix. Seller says equivalent. My tools remain on the bench until someone supplies the comparison.
We had a drawing argument go nowhere until the actual changed feature was marked. Ask for the shoulder dimensions and function on both revisions, then let your tooling reviewer assess the difference.
Then request the agreed plate as an alternative too. You need a way forward if the shoulder comparison stays unanswered, not another lap around the same bolt holes.
They say they can source the agreed revision. No supply date yet. Thanks for that alternative; I've asked them to price and schedule it without dropping the comparison request.
Who would fit and verify it if they supply the plate alone? Worth settling while they work out availability, so arrival doesn't just give you a new unopened task.