The other night when the power went out I got our my old GAZ lantern which uses the old blue canister. These canisters are no longer available but the lantern works just fine for power outages.

My question is: Is there any way to modify the connection or use an adapter to use the current canisters?

Are you talking about the puncture canisters? If so, the adapters seem to be available in the UK. Here is one I found-
http://www.hitchnhike.co.uk/acatalog/edelrid_c206_puncture_cartridge_adapter.html

Found another one, also in the UK-
http://walkhigh.co.uk/acatalog/Stoves_and_lanterns.html

FYI, this site sells a bunch of stoves I've never seen before-the brand is GoSystem.
http://www.go-system.co.uk/about.html

There are also adapters for the other GAZ canisters-the unthreaded ones. I used to have one of those stoves, but those canisters are still around, as far as I know.

By the time you buy an adapter and get it sent over, you could probably buy a new lantern.

I have the resealable canisters. Everything seems to be the wrong direction to adapt other stoves to fit the GAZ canister. You are right that it is probably just as cheap to just buy another lantern, especially because the only time I use it is at home when the power goes out. It just seems like a shame to just throw it away.

I may have to just make my own. I will have to take a closer look at the lantern to see what can be done. I have the equipment to make an adapter but I am not sure that it is worth the time and effort.

Thanks

If you have the threaded GAZ cart. IIRC MSR made a adapter for those.
I suggest that you actually write to them, even if they don't make it now
(if they even did?)
you will at least know what to search for on ebay.