Seamus,
are they that bad they need sandblasting, cost wise you can always use a wire brush atachment to a small angle grinder for the worst of it and follow with drill rotary wire brush, the outside of the wheel can then be sanded to a smoother finish (as smooth as you like) and then spray with some wheel spray paint,. This method no need to remove tyres, or take all at once to sandblaster. I did mine this way and very pleased with the result, check one of my posts here
https://club8090.co.uk/forum/viewtopic.php?f=2&t=50125" onclick="window.open(this.href);return false;. I am sure there will be other advice so this is just an option
Steve