The part number of the keyboard is 770180. That is what you should use to look it up. The -01 signifies it is US layout. I'm not sure what the 5169 number is. That might correspond to the batch or unit it was sold with.
I could not find anything of note on that board. I can't really find anything other than the ebay post that had those pictures.
The classic wisdom for WYSE boards is that old = good. The yellow arrow keys are a good sign that it may be MX. The lack of a stepped Caps lock and the relative newness of the PS/2 suggests rubber dome. There are only two known models of WYSE boards that have the PS/2 connector and Cherry switches. That model number is not among them.
But, for $40, it might be worth the gamble.