It really depends on which fitting is on the dive tank, now.
If it is a DIN fitting you might be able connect the FWB fill adapter direct. It will be hard to get your FWB cylinder off the tank once pressurized, without a bleed valve though. I would not recommend that method, as it will cause premature wear to your FWB aluminum cylinder threads. You really need a bleed valve.
If it is a yoke fitting, you will need a yoke adapter with a bleed valve.
You can see both types of assemblies on the following page, and in the pictures below. (I believe the assemblies shown include a bleed valve (be sure to ask)).
http://www.airtanksforsale.com/
If you buy either of those hose assemblies you will still need a DIN adapter; and a 1/8 BSP to QD adapter for that.
You should call airtanksforsale tomorrow, and explain your needs. I doubt there is another company that could get these items to you faster, in the US.
If you have the time to wait for shipping from the UK (about a week) I would recommend looking at BEST Fittings UK for the same stuff, only better (in my opinion). (Perhaps get a friend to fill one cylinder, now?)
https://www.bestfittings.co.uk/product- ... ging-kits/
Also, you may want to look at this thread-
http://www.targettalk.org/viewtopic.php ... 31#p287531
Best regards,
m1963
DIN (airtanksforsale photo)
Yoke (airtanksforsale photo)
FWB charging adapter, in DIN adapter, with 1/8 BSP to QD plug (my photo, of our equipment)