You can put the model in JKA, but I'm pretty sure the old JKII mods wonte work. It has to be scailed. The "npcs.cfg" file I think controles SP scaling in, becouse Dessan in SP JKII was scalled a little larger I think. He has a scail in the "npcs.cfg." In JKA that info is in the "NPCS folder" in assets1.pk3. Each NPC has thier own .NPC file with the same info as the JKII "npcs.cfg"
I think you could add a NPC file to the models .PK3 with the models info and scale it if you wanted to try and put it in SP. MP needs a mod I think. I'm really not sure I have never tried any of that. Never cared about haveing or scaleing yoda.