Now, after a messy hack, my DHO1072 is now acting as a DHO4804.
Only 1 channel seems to be working properly, possibly due to missing ADC.
well when this scope was initially released, dave did a teardown. and i then speculated with a 2nd 1072 to cannibalize the required missing spare parts from...
then you might (*in theory) be able to achieve those stated goals. however clearly the pcb where you have those input bnc inputs needs to be redone.... (*or bodged)
but lets assume that could be done, all of the channels...
then (for a more complete feature parity). there is also some unpopulated section located at the top right corner of the pcb. what was that? maybe auto trigger section for the 4000 series or something? i forget now. however ---> can look at dave's high res photos there. and check whether all of those parts can be ordered from digikey / similar suppliers. also there is at least 1 other forum member here with a 4000 series scope. who can help identify component values on that missing section of the pcb.
so you know, with a bit more work... could be? idk. perhaps transplanting some of these parts could be a bit of a challenge? like those adc sections or the 2nd adc sampler chip / special custom asic ?
... but is would be a fairly 'affordable' source to get those required bom parts list (to get another one at the same price). compared to the price of a genuine 4000 scope.