When I got my set of LCII adapters, I also bought a IIcx Adapter . . . still have the box handy, but it's empty.

I've got a boatload of boxes to go through and lost s shipload of stuff in my storage room a while back, but I'll keep an eye out for the adapter

I think someone else has the socketed CPU adapter in the SE/30 and has posted about it recently.