There ought to be a lot of spelunking supply shops
that would have parts to fit your calcium carbide lamps.
Several years ago, I used to go crawl around in caves
in southern Indiana near Bloomington.
OWW, the two caves were Sullivan's Cave and Salamander Cave. We used to spend the whole day 6-8 hours in Sullivan's
cave. One time we were about 3 hours into the cave
and I had stopped to refill my lamp and got too much
gas built up in the lamp before I struck the flint to light it.
When I did strike the flint, boom, it blew the replaceable ceramic jewel out of the front of the lamp.
On another trip we were following an underground stream
and were wading along in about 2 feet of water. I got cold
from walking in the water so I decided to walk along the
ledge. Eventually I fell off the ledge and landed funny
on my ankle. We were three hours from the entrance
so we returned and I waded in the stream to keep the
swelling down. By the time I got back to the car I had
a wonderfully colorful black, blue, and purple ankle.
I don't have my lamps and helmets any longer. I loaned
them to a friend once so he could take some friends
to Sullivan's cave. At that time he was living in Champaign
Illinois and before we could cross paths, he had moved to China, literally. He's still there and has been there about 10-15 years. He only comes back to the states for his wife
to have kids. He now has four kids but I don't think any of them were born in McDonald's parking lots.
The last time he was here, he took back a whole suitcase
full of catsup. Yep, they don't have catsup in China.