Frame size does relate to steerer length but not very precisely.
As you have the old fork at hand no doubt, as advised, knock the crown race off the old fork and measure the old compared to the new. Small chance the crown race diameter is different, most are 26.4, some 27.0 (JIS standard)
For ref, some French are in between those.
With the fork out, check the headset cups for damage, and verify they are still snug in the frame.