When I first saw this (one pic) I thought it was P85 with a full liner. After receiving it I'm thinking that it was P68 pattern done in P85 cloth sometime in second half of the 1980s. Maybe MOD had some restrictions of making DPM kit identical to current issue, so they used the old manufacturing patterns instead? Or maybe they were able to more easily acquire the old patterns from a contractor because they weren't in use any more?
One thing we have to remember about production is the contractor tries to cut down costs and cut corners as much as possible. The smaller the run, the more corners are cut to make it viable. At best this company likely got a contract for no more than 1000 or so jackets (or uniforms). Buying already printed cloth and existing patterns makes sense.
Whatever the case, it's an interesting piece.