For the Mk II Multicart - Yes. we still have a few SC-3000 Multicart PCBs left so click here to buy one..
For the Mk I Multicart - No. This is a simple project, and if you're willing to give it a go you should be able to make all by yourself. Just let us know if you have any questions.
We're very sorry, and we feel your pain. But please see our disclaimer. We take no responsibility for any damage resulting from the use or misuse of these instructions. But provided you wire everything up right and check it carefully there shouldn't be much danger of damaging your prized SC-3000.
I humbly worship the awesomeness of the god-like person who designed and built your favourite multicart and I am ashamed to breathe the same air as them :)
Please check out the credits and acknowledgements for some of the awesome references we used to get ideas and figure out how to build this in the first place.
Sweet - let us know. We're always happy to hear new ideas. Just remember this is a hobby - we do this stuff in our spare time and none of us are hardware engineers so we're keen to learn too.