I am guessing many of you know this, but news to me. #2 clock key works well, looks good. $6 on Amazon
It has been up several times, but nothing wrong in repeating a good tip In e.g. this post you find a chart over the dimensions for each number of clock key.
Try this: I recently purchased a 123R on ebay that was missing the fuel cap and key. After searching around on here, colemancollectors forum, ebay, fettlebox etc I was dismayed by the lack of availability and the price of what was available. So on a whim I reached out on katadyn.com (use the contact form: contact), who owns the Optimus brand and still makes the 123R(via Taiwan). I asked how I could procure aforementioned parts since they were not available for sale on their site, and they said they would just send them to me (arriving tomorrow). Didn't even charge shipping. I told this to a friend who was missing the flame spreader, and another member on CCF who needed the chain, and both got the same service. I wouldn't be surprised if they try to monetize their parts after a surge of requests, but give it a try they may still be generous. No, they won't be "period correct" nor made in Sweden, but for free I could care less. I was just looking to build a runner for my Optimus 88 kit.
Excellent tip, but it should be pointed out for clarity the 123 variant does not include the internal self-cleaning jet pricker; the spindle size and thus the key is smaller, Katadyn won't have a suitable key in stock for that model.
@elcarlstono Good Idea to stay and love your R , however the 123 is the best but you don't need to know that Right!!!!!!! Best for me of course. Lol
Optimus sent me parts and replaced a pump many years ago. No charge. So good to hear about good service still alive and well.
Why would you want to use some ersatz key like that when authentic replacements are readily available for ~ $50 and only $10 or $15 shipping?
A stove of this vintage, note the rings, would only be worth 50. I agree that original is best, but I would not spent that much on a key.
I bought off Ebay two 'multi keys' They cover most of the common clock key sizes and have proved very handy! An example: link Link to a set: link
To OP, Yours looks to be truly a 123 with smaller key. A No3 Robertson screwed into a dowel would fit it as well as others