the time frame has varied from a quick 3 days to a couple of weeks - but I've never had to start thinking "gee, that order is taking an awful long time to get here".
I REALLY REALLY hate his snailmail, non-searchable database, no internet ordering, luddite, head-in-the-sand-of-technological-progress policy - but the guy has a truly unique collection, excellent prices, very accurate grading and is scrupulously honest.
For example: I ordered two copies of New Worlds from him (providing dates and issue numbers) because of stories I was searching for. Unfortunately for me, New Worlds had also published a US edition with the same dates; I got those in the mail. I immediately sent them back with a note explaining the problem, requesting substitutions or a refund and got a refund check for the total amount: he didn't even take out the shipping cost.
At other times I've gotten vol 1 num 1 mags that were in far better condition than described.
If I knew him personally, I'd volunteer to put his stuff on line.