Ivan, I happen to have come across your source for this, though it'll stay under my hat
I suggest asking for detailed photos of the inside. You can buy hand-cranked blowers new from Vaughans, though they're not cheap at £344.95 + delivery and VAT.
There are alternatives of course. I use a little electric blower I cobbled together from junk that just about manages with a carefully maintained charcoal fire. Vaughans sells aluminum blower impellers (the hardest part to make) for £27.95 + delivery and VAT; I'm considering fabricating a housing from sheet metal and wood and attaching a salvaged motor or improvised hand cranking mechanism.
You can also use electric blowers salvaged from stuff. Hair driers and shop vacuums set to 'blow' are classic examples, though they are loud and have far too much air. Air blowers from orphaned tumble driers are apparently quiet and cheap and free, but I've never tried them. Car heater blowers are suitable too.
A few points to remember about blowers:
1) You can make them from scratch
2) You can modify them or make from parts of other things
3) You can scrounge them from stuff
4) If a blower is electric you must know how to feed it correctly and do so; if it needs 12V DC @ 3A, give it that.
5) Air gates are good.