Thanks my67xr. So I am not going down the complete manifold path. Some aluminium, a TIG and my rubbers and matching spigots could be used to make a good replacement set. The same rubbers and spigots could be used on any bike that has the same carb bodies.
Here's the measurement's from the 2KRs' BDS26 I forgot to add that the groove is 1mm deep, so 32mm o/d