http://www.ebay.com.au/it...84?hash=item2ed6461210

Is this a stupid question, but since i have to file out the holes, can i not file them out to a different (smaller) diameter and buy the bolts to fit from my local bolt shop? Obviously, they would still be high tensile and have the non threaded shank, but it was just an idea to avoid paying $36 for 4 bolts......

yes, you should be able to still get the right thread bolt with an imperial shank and open the hole to suit. to be honest my filing was so bad I doubt the shank did touch the sides anyhow, remember its friction between mating surfaces that prevents movement not the bolt in shear.
 
JP

Thanks everyone for the help!