Hi Chris,
I used engine bearings from a scooter. They have an outside diameter from 30mm x 30mm the inner bushing has a length of 35mm and 10,2mm for the screw.
Maybe the length of the inner bushing needs to be adjusted. For me it wasn't a problem because I changed/reinforced the brackets.
Maybe I could help you.
If you are interested in this bushings I'll look where I ordered it.
Best regards from Germany,
Fabian