Removing decals from tanks with special skins

I’m porting a skin for the IS-2 1944 on to the IS-2 No.321 from an event a while back, however I’m having a problem with the number decal present on the turret.
The skin I’m porting does not display decals over the skin which is something I want to keep but the ‘321’ number decal displays over the skin. Is there a way to do this?