Help with assembling a jig

Its to be used with a router that has a 5/8th bushing and a 3/8th bit to make some 3/8th slots in a board or piece of plywood

what I’m struggling with is what tool or machine I can use to create the jig with

here is a drawing with some dimensions

[IMG]http://i106.photobucket.com/albums/m249/PhotoMaster101011/asdf.gif[/IMG]

also I just want to confirm that with that bushing and bit combo that offset is 1/8th correct