You could always use a drill to carefully bore out a larger hole in the boom and extendable arm so that you could use the chinook pin????
I have a North boom, with teh part you need, BUT, it is still in one piece and works, except for some tatty grip, whihc I am keeping for a back-up.
I replaced it cos it's old.
I'm thinking you could go to a lot of trouble fixing your old boom, but the pics shw a lot of corrosion, and brittle plastic, and I'm thinking it's past it's reliability date.
replace the full end, have said that looking at the corrosion, it maybe time for a new boom trust me if the end is like that the days will be limited sorry about the bad news
yes the pin is corroded but the boom is full carbon so I don't think that a problem if I can find a new pin and a new plastic locker. 
Hey julian,
Have you tried simon yet? He is the local north dealer and has hundreds of bits and bobs.
What's the inside diameter of the part you are chasing? I've got a few bits and pieces floating round here.
If you get onto al green pretty quick he carried a fair bit of that sort of stuff also- I had identical to the black one you broke on an old dynafibre or something and got brand new replacement for cheap from him.
hydrodynamix has something similar listed on their website for $10, they don't say what diameter boom its for but say it suits other brands of boom. I think its the type that twists open, black in colour
cheers
Is that the same end that north used on the alloy booms cause i have one of them with a slight kink in it i keep as a spare. Have you tried Sunshine coast sailboards, they deal in north
Thanks KenHo and fitz66 for telling that you had the bit I need 
By the way, I tried Sunshine coast sailboards and they contacted North for me. They're answer was that this pin licker is no longer available 
At Mk seven, I don't know the inside diameter but it's looks like pretty standard. I'll check this out and let you know. That's would be fantastic if you had one!
ANd who's al green? 
Hi there I have 2 Gun boom fittings that you are welcome to they are 30 mm on the boom end and 26 mm on the extension end,just let me know and I can chuck them in the post.
