Just find a radiusing block to fit your radius, and then start out with about 150 grit sandpaper, then work your way up to very fine, about 280 grit. just take your time and make sure that you dont eat too much wood on one side like happened to me the first time i tried radiusing my own fingerboard. then just finish the board how you like and you are good to go
have you tried the lutheir at Guitar X in Denver? his name is Steve Cox, and he did the same job for me about a year back on my 5 string fretless, and it plays amazingly. he only charged me $45 for doing this, oiling the fretboard, and doing a complete setup on my bass. Guitar X is on broadway (i think). look them up on their website
www.guitarx.com. they also have some fun basses to play down there.
hope this helps