I belive the Escom 1D4 has all the mobo fixes done too so i havent found those more incompatible... Both 1A and 1D1 was made by CMB and were some of the first revisions with out price cuts in the components.. Later boards may have had different capicators etc such as the terible 2B although there are exeptions ...
As for the difference i am not sure i used to have a 1D1 it had issues with my Delfina so i swapped it for one of thoose new old stock mobos "1D4"
