I build things from parts - sometimes repurposing dead synths

I’ve come here to learn.
I’ve been building synths out of microcontrollers + DAC and hacked into various toy keyboards and used more and more arduino software libraries or my own code until it was functional. So I built a series DIY synths and i’m building a whole set up out of them. Something about making them creates great satisfaction - I used to play guitar professionally. Now I’m learning to play keyboard … and I always liked stand-alone musical instruments more than everything getting virtualized into a computer. It seems like that makes sense to a lot of other people.

At one point I wanted to build a keyboard from scratch but - well its not easy at all. So I’m always looking for old parts, keyboards to use for parts or build around something that was a useless or broken toy keyboard and make it useful. I have about 4 synths so far - and I can make midi-controllers. I’m building one out of an old Casio that has no velocity sensitivity - there are a ton of buttons I will try to use to help switch functions or edit sounds.
I’ve written arpeggiator software - i mean such things are done a lot in various communities.
At one point I was giving up but then I found Syntaur on youtube and got all kinds of ideas how to push forward. I repaired broken traces. I fixed some carbon contacts with a pencil (i found that advice elsewhere). One part of this board was so corroded that the carbon was just gone. I had to drill holes and insert wires and use bits of wire to make metal contacts for the rubber keyboard contact to send the on/off voltage for a couple of keys. So far that is working.
Then I wondered about lubricating these old keys - first time I noticed how bad it was after keyboard contacts board was reinstalled. So … anyway, i’m on some mad journey of restoration/rebuild or making new things.
One thing I have wondered about suppliers make the spare keyboard and circuit-board that is order-able so you can build everything else - its not for repair but for something new. I could build it onto some wood and make my own Frankenstein synth or build something semi-commercial to sell or give to friends.