Many thanks all....
I'm now thinking it would be folly to buy one of these from my regular music shop, & that I would get a better instrument if I go for a reconditioned & retuned item instead.
So now I need to consider whether I would need more than 20b, or not, & what that would cost me.
One other thing I need to consider is how loud these might be, as I would only be playing at home for my own enjoyment.
I have read on the forum that material baffles could be used, would they have a significant effect on volume, or would it be down to how fast I operated the bellows, (like hard or soft blowing on harmonica reeds).