How tight should brake lever clips be? I've ordered some second-hand handlebars from one seller on eBay, and brake levers from a different seller. Both claim to be 22.2mm diameter but the clip on the levers (as photographed) will be a very tight fit if it will fit at all.

Am I right in thinking that the clip as photographed doesn't come apart into any other pieces?

The levers do say 22.2, I can't find any markings on the bars. Am I right in thinking that 22.2mm bars and 22.2mm levers go together?




Figure 1. Clip is flush with end of handlebar




Figure 2. Clip raised slightly from end of handlebar
The clamps most probably got a bit squished in the mail. You should be able to make them a bit larger with a pair of needlenose pliers. 

I would try expanding them (without the tightening bolt) so that they fit over, then bringing the two arms together with the pliers and putting the bolt in.