I'm as polite and helpful as it gets with sellers, and buyers. What happened here is just one of many occasions I've encountered over the years. Once I visited the seller it became clear it was a reluctant sale, and he had hesitated somewhat in cooperating for a number of good reasons. I reckon if I had pushed online it would have been withdrawn from sale. Once there, we had a great interaction, ending with us agreeing to do some further business. As it happens, I was able to visit another seller right next door whom I contacted near a year ago about a bike, who never provided me the measurements I requested either. I had my tape measure, my eyes and legs so a deal was struck there as well. In her case, the hesitation was due to an emotional bond.
I tend to focus on poorly described items, being sold with a story. Especially gear sold by sellers who see the minutiae as rather unnecessary, as they are handing over perfect goods at a fraction of their cost.