Guessing brake size

I told him it would have 9" or 10" drums but without removing the wheel wouldn't know for sure.
Not true for the fronts. The 9" & 10" drum spindles look totally different. Just peek under and compare to Google Images. The 9" has a curved goose-neck that comes in from the fwd or aft side (forgot which).

The disk spindle is also different, but of course you would see the rotor anyway. I would expect that all front disk cars had 10" rear drums.