[Leo M]

Lots of options for 3-position, closed-center valves. The hardest part is finding them in 12 VDC. Try Grainger Stock # 2G449, an ARO A312SD-012-D valve, about $114 in my older catalog. Or # 4TR82, about $100.

I didn't see anything in McMaster-Carr, but just did a quick look.

You don't have to use SMC - if they are backordered, go to another vendor (this is just like real engineering life; things you need are always unobtainable).

These valves are great additions to the legal parts - energize one solenoid to extend, energize the other to retract, and de-energize both to hold position.