I have a gripe with grading companies, no not just one, but all of them. I think they often bite when it comes especially to grading foreign coins. The other day whilst I was out of town I occasioned a Queen Anne Crown that was minted in Edinburgh in 1707, with the E mintmark. To me it was a fine, but the TPG holder said it was a VF-20, the dealer wanted VF-20 money. I offered F money and he took it, on getting home I liberated poor Anne from her plastic tomb and let her breathe again. It was graded by one of the three top tier companies. And the plastic went to the recycle bin.
VF on that ? Queen Anne crowns are impossible to find, but being honest, at best that is a boderline F, with the haymarking on the obverse. Good for you !
Haymarks are fine lines often found on older coins in higher grades - we call them hairlines here in the US. To be honest, I see no signs of it in the pics of this coin and I wouldn't expect to, not on a coin in this condition anyway. Here is a coin with haymarking - a 1911 Proof half sovereign that suffered some mishandling at some point in its life.
It sounds to me that the dealer knows the difference between F and VF and was hoping that either you don't or that you would be so impressed by the "authoritative" label on the slab that you would accept it as such. I doubt any of the better British dealers would have offered it as VF to their customers. Good for you for being able to look, see and think for yourself.:high5: