Hello folks, bear with me as I'm a new convert to the stove addiction (3 so far after having got the first for a quid at a bric-a-brac fair).
My third and most recent purchase is a Primus No.1 which having used this sites very handy dating facility seems to be from 1915, having the 'E' stamp on the base. It also has either instructions or manufacturers details in at least 10 different languages stamped into the brass. These run from French to Arabic, Chinese/Japanese, Greek etc.
Once again, thanks to this site, I can let you know it's of the 'silent' type (I only have the inner cap).
Okay, after all that my questions !! Is it indeed from as early as 1915, is it rare and yes, I suppose I would like to know if it's worth much.
Any help would be appreciated and any assistance in finding an appropriate outer cap would be great.
Cheers folks and a big thanks for those who run this site.
Nick.

Basecamp has outer burner domes, I believe, and there are other sources as well. Click on Basecamp's ad at the top of the forum.
Questions of value are always raised by newbies (which most of us have been within a rather short time ago!).
But value of an object always in the final analysis means market value, and for these stoves as well as for most mass-produced personal collectable property these days this means eBay.
The most anyone can do to project value is to give a range based on auction histories. On eBay you can find completed auctions on particular models and make some judgments that way. My observation is that generally in the collector's world fixed-leg domestic stoves tend to get less action at auction than collapsibles, whether they be thought of as domestics or camp stoves. One of our greatest authorities on these stoves is Peter Watchorn, who posts from time to time; his first love is indeed the fixed-leg domestics.
I think that most of the collectors, at least those who spend a lot of time here, have an outdoors-camping-hiking orientation, which gives a bias to the old camping models. Hence the name of Ross' site!
Keep collecting, haunt eBay, and in short order you'll know about as much as anyone else about value.

Following up a bit, here's a suggestion. Go to eBay and click on the search function at the top. Then click on Advanced Search. Enter primus stove and checkmark completed auctions only. This will give you about 70 completed auctions for the last week or so. You will see that none of the prices are real high, and the highest are pristine campstoves with fine tins. There were a couple of Primus #1s that went for modest prices.
A 1915 stove, however, is older than the vast majority on offer. The condition of the stove is the most important consideration usually, then age, or so I observe.