Hi Waynne

They’re more than likely going to be to US standards which are a different size to UK AGS types, I’ve investigated these before and unfortunately they’re not a close match

John

http://www.ralmark.com/products/
Although a US firm I know they have supplied a Waco glider project. This is a quote from their website: These pulleys are in continuous production in our factory. Derivatives of these standards can be offered for special applications.