No big deal. Go to turntablebasics.com and look at their table of mounting dimensions. As long as you have enough adjustability in the tonearm mounting slots you can adjust the overhang and the angle to get correct alignment. For 249.5mm P-S the overhang should be 15.51mm and the angle 20.65deg. For 239.9 mm P-S the OH should be 16.09mm and the angle 21.41deg. Recall eff length = PS + OH. They make a very good protractor.
