New "Old Guy"

Hi all,
I'm new to the site and relatively new to this kind of thing in general. Just about to retire and I have a 67 fastback Barracuda that I want to get working on. Put a new polygraphite front end in it a few years ago and it's been just sitting around since then. I worked in a Plymouth dealership in the late 60's and remember when this car was new. I want to get some decent wheels for it but the 4" bolt pattern really limits things. Any one know where to get some of those spacers to change to a 4.5 " pattern?

Thanks,
MJDCWO