Yes, those are diodes. You can order them from Cherry with diode or a jumper.
The diode/jumper adds stability if the switches are PCB-mounted. Jumpers are useful also if you have a one-sided PCB.
BTW, use low speed on the dremel when cutting plastics, otherwise you will melt it more than cut it.
Let me suggest also that you get a set of "needle files", to use for the detail work. They are cheap.
(oh man... posting this messes with my 1337 post count)