As I have mentioned before, my magazine blew up last year and shot the inch long core across the room and through a cardboard box. I managed after some effort to contact Iron Airsoft but they didn't have any spare mags in stock but said they were planning to do another production run this May. I have now contacted them again and they do not have any plans for another production run at present. 
I have tried everything to get the valve working and have done exhaustive searches for a possible replacement valve and no luck.
I also looked for magazines that looked similar and have come across this:
It's for a WELL G96.
The arrangement of the valves is similar although the gas release valve is a totally different shape. I wonder though if it would fit inside an SMLE magazine shell?
[youtube2]Zsd0R6lsALs[/youtube2]
Then with new feed lips and some reshaping of the top it could be a source of replacement mags
Hi Russell
Sorry to necro post but I may have a solution for you. I had a spare magazine that did something similar. Basically you need 3 parts made up. I think in your case you have one part which was the top part of the valve. What I suggest is you get it trimmed and have some make you a new bottom bell end to hold the sealing o-ring in place.
You can see here the outer part of the valve, which you should still have in your magazine. In the photo it has got the lower sealing o-ring on it.
The bottom piece I made from two parts, as in this mag the brass plunger had shot off. I used an old brass tube valve stem which I turned down to approx 7mm and 6mm to fit in the outer. The top was filled with a brass rod and the bottom left hollow.
In the hollow part I used the bottom of another valve which I interference fitted into the top half. This would then be measured up and once to size it would be fitted and the two halves steel epoxied together within in the outer.
The third part you need is a fine spring that keep a slight tension so that the valve closes. The plunger sits about 2mm proud from the valve outer.
I hope this helps.
PS the valve from the G96, Wells or G&G gas L96 rifle (shown in your pic above) doesn't work, as I own one of those and tested the valve.
I fortunately have a lathe and took the time to turn and fit the new inner.
