Hmmm...OK, well, I still hate that Acidlab sequencer being in there. If you had the ability to trigger some of the other states it has via trig/gate pulses, it would rock. But they obviously built this to be as close to the TB-303's underimplementation as possible...which isn't good, given that you're talking early 1980s sequencer tech, and things have gotten a lot more interesting since then.
So...keepers: all of the Tiptop modules, the 2 hp mixer, and the A-130-2.
Now...things that have to be replaced are the weird 3-pole VCF (or something suitably acieeeed-ish) and the sequencer. And that weird filter ain't easy to replace...but this is EURORACK, dammit, so...yep, replacement exists! Check out DinSync's VCF303. Yeah...the filter AND the oddball EG/accent circuit that it also needs to get that sound. Perfect! Smaller, too! As for the sequencer, it needs to output that important accent pulse AND have the proper glide behavior...which gets us to the Copper Traces Seek. Multiple sequence memories, all of the outputs needed, plus a bunch of extra trickery for less $$ than the Acidlab, and in far less space...but doing an improved version of the same thing.
That's just for starters...I'm thinking that I'm going to bang on this for a hot minute, see what I can toss out...