If it's a must for you to use these certain wheels, then change the hubs, somehow.

I would NEVER mess with anything like that - spacers, wobble bolts, spiggots, or ANY kind of adaptor etc.

Personally, wheels (and other "road gear") are VERY important to me for safety. I always check tyre pressures/condition, wheel condition, weights, everything. Always decent tyres, I NEVER curb an alloy, and drive annoying sometimes to avoid this! All through safety. I just think wheels are very important, and shouldn't be messed with like this.

There's a few horror stories about, regarding people modifying wheel fixings.