Data packs fallback texture for non resource pack users ?

Just wondering if it’s possible to set a normal texture to load when a user without the resourcepack that the data pack is linked too connects to my server. 
For example I have custom armor textures using a smithing transform recipe but when a vanilla player connects they see no armor model/missing texture item model. Could I make this use the diamond armor defaults for those users ? 
I previously used cit resewn and it was great as vanilla users that joined would just see the vanilla diamond armor players had changed the skin of. 
Thanks if you have any info even if it’s just a no that’s impossible ❤️