Dom, the lowest leaves on hard wood on your tree are true to variety - it is better not to judge new leaves on green growth, especially during rapid growth. This is one thing I agree with Dan_la/Dan Abadie on completely - speed of growth seems to impact the shape of leaves to a degree. My green growth on RdB (top growth) can vary to look a log like VdB/Negronne, but almost all the grey-wood growth is true to variety.
None of the leaves on the variety the eBay seller has posted are true to variety - which can mean it's not varietally correct.
However, his fruit is absolutely NOT a match to RdB. If the fruit doesn't match (if it's that far off), it's absolutely not varietally correct.
His fruit in the auction looks more like Paradiso, Sal's Corleone, Brunswick, etc. I'd say Paradiso because the leaves are long and fingery like Brunswick on the lower growth, but it also has some fatter leaf shapes, and the red stripes down the side remind me of what I've seen of Paradiso.
I like how the eBay seller has posted "Ronde de Bordeaux family" as if there is such a thing? I'm not aware of a "family" or even "variants" of Ronde de Bordeaux - you either have Ronde de Bordeaux it or you don't.