I don't think he wanted the actual speed, just the ratio between the two as he only asked for one roller. As I said, he may be wanting to replace a drive gear and wanted to get the right size.
Course the speed could be figured by counting input revs vs output revs of the rt angle gearbox; probably 1:1 so then it's just a matter of counting driven teeth vs drive teeth and relating to a 540 pto.
I thought about my numbers today and the initial value was correct. Since the pi multiplier occurs in the numerator and the denominator and this is a product (axb, not a+b) sort of thing it cancels and it's just a matter of the roller diameter ratio transferred to the tooth ratio.
Phew I'm getting rusty.