[Arran]

 I would replace the whole top/sides, or at least the top two layers of it. Anything is repairable given enough time, and or money, usually when veneer cracks like that it means you have dampen it a bit first to get it to expand to fill the gap before gluing it down. As for the front panel, or indeed the whole cabinet if you want to go that route, Steve has some cabinet parts available for model 19s I think. No matter what you do that cabinet will likely have to be taken apart to be repaired. I don't know how far you want to go on this set, but if the chassis has major rust, or the set is missing parts, it may be worth holding out for a better model 19B and keeping this one as a parts set.
Regards
Arran