I am not a computer nerd but I think a cockpit that is programmed as a graphical map or with funktions triggered by pressing a key is something complete different. So I don't see how one could map keys for a panel that is programmed as purely clickable.
I know the clickable panel from Battle of Britain Wings of Victory.

I didn't like it that much because the mouse is very imprecise and it takes some time to move it from A to B and back to C. While in reality you'll be much quicker with your hands (or with keys). Imagine doing this while in flight. You'll take your hand off the stick for quite a while whereas in reality is was much less time used to press a button.

And you have to make mouse movements rather slow because otherwise you would overstear with the mouse and you would spend even more times in regulating the mouse cursor position.

Furthermore you have to press a key to toggle the cockpit clicking function on because the mouse is needed in other modes to. It would be quite tedious to click on the in game map and to actuate a switch through it.

But above all it can be very difficult to click the right button if they are very close and the mapping wasn't that well done. This was the case sometimes in Battle of Britain Wings of Victory ...

No, I really think that key pressing is much more convenient and realistic. If you want to build a cockpit or not.

Btw I do believe that building a cockpit may be not that expensive as one might guess if you stick to simple solutions and not first class materials. Plywood can do btw. Why not detach the keys of an old keybord and wire it accordingly?