The SE and SE/30 are indeed fully compatible but some analog boards (without further modification) are better than others...

1. Look at the power supply. If you can find one with a black switch choose it over a white switched supply. (The former is a Sony, the latter an Astec; the Sony has consistently been more reliable in my findings).

2. If you are swapping with a board made in 1987, make sure it doesn't have the dreaded rat cage fan.