how do i extend a tuning shaft?

[jbivy]

So im putting a late 50s fm tube radio into an empty 20s case. I need to extend the tuners shaft a good 5 inches. what will i need to do this?

Maybe using another piece of 1/4" rod, with a collar to connect them?

If im getting the terminology wrong, im sorry.

but any help would be appreciated. im making this radio appear stock from the outside, not changing anything internal. in case i find an original chassis.