This is an American made Primus No:1 - although marked No:1 it's catalogue designation was 103. As you can see from the pictures the tank is different to the Swedish model. The pump is removable & features an unusual non-return valve (NRV) - this was not however unique to the American models. The pump itself is also unusual & I haven't figured it out yet! I thought the pump leather was missing but there is a leather washer that seems to do the job. The silent burner was standard on the American No:1 rather than a roarer & the inner burner cap actually screws to the burner. For more info please see this 1897 catalogue. The model was the core of the range & sold in varying permutations - without legs, within separate stands, ranges & heaters. The cast iron pan ring, outer burner cap & pump knob are replacements - all missing when I got the stove, plus a new jet & washers for filler cap & burner.