I’ve used both the Festool adapter mentioned and the Leigh adapter 704R. They both fit the router base just fine. Don't forget to use the Festool 492187 Centering Mandrel to eliminate any slop between the bushing and adapter. I’m pretty sure the mandrel came with the OF 1010 router kit.
I agree, except that Mandrel did not come with my 1010.
I recently got the Leigh 704R for my OF 1010. The problem with the Festool part 469625 that came with my OF 1010, is that it's too tight to adjust with the centering mandrel, the Leigh version is smaller and is adjustable. However, if you order from Leigh, request they send you a pair of screws to secure it to the OF 1010 base. Mine didn't come with any, and I couldn't find anything locally that had a thin enough head. I contacted Leigh and they sent me a set for free. Great service!