I see that there seem to be two different "standard" blanks for router plates - square and rectangular. I was given a 6 yr. old Craftsman router table and base. The router plate that come with it looks like swiss cheese it's got so many holes. Of course, none of those holes match up to the Craftsman router I just purchased.

Is the Craftsman rectangular plate interchangeable with other rectangular plates? Do I have to go to Craftsman to get one or can I just order one online somewhere? Are they a common thickness? Can I just go to Tap Plastics and get one made or would that be too flexible to make a plate out of? Any help would be appreciated.