If you will be less picky, there are some old terminal boards that can often be had for cheap such as Wyse, Link, Reynolds, etc. that have 2 units enter and 2.5 units ctrl, but you will have to settle for abs doubleshots.
It probably would be better to redesign... if your goal is to make the board more symmetrical usually a 1.75 enter is used to match the caps lock on the other side, with both shifts as 2.25 and a 1.5 backspace. Those will still be obscure, but not quite as obscure as what you are currently after.