forgive delay in responding, just saw post:
Ju52 - in "class" file change:
JU_52_3MG4E Ju-52/3mg4e de 2 3 0 193901 194612 none Ju-52_3mg4e
to
JU_52_3MG4E Ju-52/3mg4e de 2 3 0 193901 194612 none Ju-52/3mg4e
It worked for me - will be able to assign skin and will appear for edit. Good luck.