So I have a Meatball clone and the MB Sharkfin both on my bench, in 'build' status.
I was thinking about doing a Dig Dug, but would that be a little redundant, with sample/hold side of the Fin? (i.e. the automated step thing)
The automatic step on the Dig Dug is LFO-controlled -- always at the same rate no matter what you play.
The steps on the Sharkfin are envelope controlled - they change depending on your playing dynamics.
I have a Meatball and a Nautilus :) They're different from each other, despite having common ancestry fairly closely.
Sounds like you have a good excuse to have fun with a soldering iron to me, tell the missus it's "finding out the nuances between them"