stillcovalent

I ordered a pair of Salsa Cross lever (40$ + 18$ shipping) on ebay, which arrived today. The seller did not mention about the diameter of the clamp and me, being new to fixies, only realized it's a 31.6mm clamp when i unboxed it today... I can return it for money back but that means i lose an extra 20$ on return shipping!

Which size should I get for my brake lever? 26mm? Or is it possible to put some spacer/adaptor on my handlebar so that I can install the 31.6mm brake levers on it?

Thanks!