I think he is the one selling that cylinder on ebay.
Atleast the ebay name matches his user name here.
How about getting some actual specs. Use a set of calipers and measure the pin hole diameters, rod diameter, cross-tube width, etc.
And where did you get "more than 10" of them if that is indeed you selling them.
If you post some actual dimensions, there are pleanty of kubota users here and we might be able to identify.
Oh, and what makes you sure its a kubota cylinder. All the kubota cylinders I have seen are kubota orange.