Switches are NEC branded linears with grey top housings and black sliders.
Mount is nearly identical to, and is two way compatible with, SMK vintage linears but seems slightly larger or tighter toleranced.
Disassembly is also very similar to SMK vintage, two side tabs hold the bottom and top housings together. Unlike SMKs however there are a second set of locking tabs on the top housing which engage with the mounting plate.
Clearly inspired by SMKs switches, even though all the parts are different.
Key travel is a full 4mm, definitely an improvement over SMK.
Weighting is fairly light, around 60 grams bottoming out.
The key feel is pretty good, decently smooth and nicely weighted with a deep clacky sound.
The stabilization of the larger keys is done with dummy switches, but these don't suffer from the binding issues which SMKs do.
In fact these are almost perfect, even better stabilized than some wire ones do.
Special switches have paint applied to the top of the slider to indicate locking switches or different spring weighting. These gold painted ones are slightly lighter such that the combined weighting isn't overbearing.
The board itself has a different internal designation, TC-856 vs TC-806 and Revision 3A4 vs 3A, as well as an updated PCB with additional components and circuitry.
This particular unit has also had a modification in the form of a custom controller board which has been Velcro-ed to the bottom of the case. I suspect this is to convert the the keyboard for use with some proprietary computer.
Overall this seems like a fantastic keyboard, definitely looking forward to converting it for use on modern computers.
