I decided to make this board compatible not only with IBM PCjr, but RC2014 too :)
And on the right side of the board it may even have optional NI-15 interface for nedoPC-85 ;)
So this board is for 3 different retro computers :)
Inside of IBM PCjr it will fit this way:
It will be some extra board that connects WizNET module with PCjrNet board and as you can see shape of the board is very tricky...