Lance, so is your donk manifold grooved on that face to fit the seal with one raised side, or modified to fit the steel backed seal? Are you wanting/needing to replace the seal without tipping the donk away? If you need the steel backed style, you could make up a steel plate grooved on each side to accept an O ring, or bond some RTV to the plate with the help of a wax mould on the face to form the semi-round.
Lance, you have two choices, get the right seal, or change the manifold to the new type, I had the same problem when I did mine. I have changed to the late stile for others and it fixes the problem! Regards Andrew
Lance, I reckon I have 2 of those older style steel reinforced seals here I bought from Florin Tractor last year that haven't been used, I was going to use them on my D4 2T and D4 7J but ended up using the newer style non steel type successfully on the 2T with Eddie Bedwell's blessing, I still have to refit the head on the 7J diesel, I'll send you one if you would like to try it.
Mike