Re the J94 this was totally a DJM model and Hattons only commissioned, like others did, livery exclusives.
KMRC still market new exclusive models under their own brand e.g. the new tooling 0 gauge D1410 LSWR covered vans and CDA hoppers (developed with Dapol) have both been announced in the last 9 months) and will continue to do so, watch this space.
This in addition to any models developed for the EFE Rail brand.
Re Rails of Sheffield the Terrier was indeed commissioned via Dapol, they have not yet developed any RTR models directly in house.