Is it possible to add buttons to a 4 button neo candy 29"?

I am playing it with an MVS 2 slot in it. I was wondering if it was possible to make it a 6 button cabinet. I don't know anything about this stuff so please understand if it is a stupid question.

Yep, as long as there is enough space for the buttons.

The older MVS-25/29 cabs control panels suck for 6 buttons as there is limited space...it can be done though (but still sucks)

I have an old 29inch cab and I don't think it can.

Sure,

It can be done, you just have to have the right hole saw & take the time to do a good job. I just got through adding 3 buttons on both side of my Super Neo 29 Candy Cabinet so I can play both Neo Geo & Street Fighter type games. Just wire the extra buttons to a Aux. Harness and your set. I mainly use the extra (kick) buttons on mine for my Capcom CPS II games. If you want I'll email you some pic's of my cabinet. I hope this helps.