1940 World War 11 gas mask

At the bottom of the mask is the date 25-9-40 and other letters that I can't make out. Large Straps are intact with the writing of No 4/ M K 3 Dunlop 20-10-40.  The glass on the goggles is not broken.There is a small tear at the top of the mask. The connector pipe to canister and mask is not torn or broken. The canister has a bullet ?? hole entering and existing. On the one side the hole has been closed with Pratley putty as in the images above. Above the canister is engraved 28/3/41  O 8S8 At bottom is engraved AC2. I don't know if there are any contents is the canister. Postage RSA including insurance R55.00  .