I'd give it a little more time. You don't mention how long it's been from the sale, or how far he is away. In the states, we drive pretty far to pick up things and do things simply because driving is part of our culture and everything is spaced out pretty far apart. Weigh in shipping costs vs driving and time costs and depending on the item, I'll drive 2/3's of the way across the state which is about how wide the UKis.
I'd do it for a rifle I was interested in simply to verify condition before purchase, plus we don't require government interference on person-to-person sales of long arms.