Worked perfectly! Before the post there was no avastar-mesh in the custom properties as I deleted it along with the shape keys and original vertex groups before adding edges with knife and using a mixture of sculpt mode and edit to the mesh for its new shape, so I find it odd that it was still identified. Mainly used a copy of the default female so I could keep the default UV maps for texturing... or so how the original idea went and it may or may not been the one thing that kept that link.
Using the freeze mesh tool fixed everything though without having to remake or edit anything! That and your response time is quite impecable.
Thank you for everything Gaia, you're a true lifesaver. <3