You may have discovered by now that we ourselves - Leopard Workshop that is - now offer 2A5 barrels.
Please take a look here:http://leopardclub.ca/workshop/LW018T/
We do different fittings for Revell or Tamiya. The Tamiya barrel will also fit Hobby Boss.
We also have 2A4 and have now introduced Leopard 1 barrels.
All the best