The underframe and bogies are similar, so the drive system can stay the same, the ends of the hoods are straight up and down though on the H class but slightly angled back on the 800 class, some styrene sheet and filler fixes that problem though. The cab need to be moved forward on the underframe and that is no great problem and a new short hood made up to finish it off. I am not looking for a dead exact model just a near enough one without hacking the body about greatly.
But so far it has come out reasonably well and gives me another loco type for my roster, so here is a photo of it in a rough state as far as it has got. Still a heck of a lot of work to do on it though, the cab windows need to be altered or opened up lengthwise but the rest is all done, in this photo it is not glued together yet as it is easier to work on it as smaller pieces but once done it will be glued up and then glued to the underframe and thus can be removed from the mech exactly the same as the original model can.