Why not Robin, it's only 3 or 4 (can't remember the exact amount) ball bearings and brass springs. It really isn't that difficult to repair if you have the parts. The larger plastic rear section and internal bayonet ring part rarely get damaged and certainly don't get lost as they are so big (unless you drop it off a cliff or down a drain etc). There's plenty of tutorials on line to help if you get stuck. When mine self destructed, like I say I found everything except one spring, and even without looking on line, it only took me a few mins to understand how it all went together, and with the help of the aforementioned tape, has continued to work for the last 6 years or so since it self destructed.
Here's a good repair tutorial:
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