I had this problem a year and a half ago. My router came with additional, longer bolts specifically for table mounting. It is a KING Canada router, cosmetically at least identical to the 3612C. I used them to mount the body AFTER removing the plastic base. You would NOT want to keep the black base as it would make bit changes difficult at best and severely restrict the diameter of usable bits at worst. I searched the local hardware stores for bolts that were a little longer than the ones the router came with. I found them . . . but they did not have the proper tapered heads to sit into the mounting plate. I had to make do with the ones that came with the King for this reason. This meant I had to drill into the phenolic a little more than I would have liked. So far though, they have held. Likely, in the UK you'd have better metric suppliers than I have access to in Canada. The bolts are M4 or M5, I don't recall for sure. It seems clear your 3612C did NOT come with an additional set of longer bolts, as mine did. So, I think you definitely WILL have to get longer ones!
I say "I think" because your plate may be a little thinner than mine?
I don't recall if I used the drill press or not to make the holes. But my plate is phenolic and yours appears to be aluminum. You'd not want to mess that up so I'd use a drill press in your case.
Last edited by dawziecat; 05-22-2011 at 08:50 PM.