Thank you all for your help. I have learned a lot from this thread. Here is an update.
I tried to purchase from a USA site and a European site and they both wanted about $30 shipping for LED's costing less than $5. That wouldn't be worth my while because the flashlight is only worth a few dollars.
So I tried Ebay again and instead of searching for "led flashlight replacement", I searched for, "Led pcb" and I got lots of hits that were far more reasonably priced. So I ended up getting 2 bright led's complete with the board for about $4 ($2 each). I am guessing that they are similar to the original specs, although not as good as the others that have been recommended.
Thank you again for all your help.
Kind regards
Chris
Your flashlight looks very similar to low-cost 3xAAA "zoomie" lights typically available $10 here OTC, and sometimes am able to be 2-pack for under $10. Yours should take an 18650 and I use a PVC tube spacer. Running on 3xAAA is not viable for very long at high brightness/current.
You would not specify 4.5v for the LED, it would be power e.g. 5W; 4.5v nominally feeds the driver circuit but will go lower as cell(s) run down.
On high (these specify 350 lumens) I measure about 1.2A at 4v (Li-ion) so consumes about 5W. If you want similar brightness, 1W or 3W LEDs will not be sufficient.
I have not figured out how to get mine apart without damage, and no real need to so far other than curiousity. Mine have five modes: high/mid/low, flash and SOS. Cycling modes is annoying.
I like fixing things also but can't see paying excessive prices for replacements. Perhaps you could salvage LEDs from something like a 12v automotive LED spot/worklight, if you can find a suitable one. Many use "3W" LEDs although driven at lower power for better lifetime. Your present board could overdrive them though unless there is a way to reduce drive current, if it is as high as I think it may be.
Missing spec for replacement LED is beam width which will affect the beam characteristics. Perhaps someone knows what it should be for this type of setup with the lens, I don't.
Dave