This is one of the original pattern Pyros with the innovative combined filler and pressure pump assembly, and a modern top plate to make it usable. Patent Pyro stoves do keep surfacing, but relatively few seem to be operational, these original design examples especially seem to be viewed more often as museum piece curios. So what problems did we start with? First there were the disintegrated elements in the pump and NRV systems. All the bits were there, either in the bottom of the pump tube or amongst the debris inside the tank, but not all recoverable from a practical point of view: The leather cup carrier was reusable, but the rod end 'nut' had no thread anymore; with a little rework of the rod end thread a modern nut had to be substituted. As can be seen from the photo even the remains of the NRV carrier took some extracting, the spring, cup and broken fragment were recovered later from the tank bottom. A replacement NRV carrier was made by butchering and then counter sinking a modern NRV to get a base fit on the pump tube end: The whole NRV is all tank side, the photo above just shows the first step in the modification process. Secondly, the burner unit was in a mess. Someone in the past had tried to solder the whole riser to burner joint, rather than just replace the washer . In the process significant damage had been done to the unique horse-shoe spirit cup. Once again the problem was one of trying to salvage as much as possible, one of the perils of dealing with irreplaceable non-standard components. And, thirdly, the flame spreader was missing as usual, but of course as SMolson explained in his excellent posting this is not your usual burner/spreader arrangement. Luckily, although this is a '00' size burner, some (but not all) No.1 size burner spreaders can be found to fit: Before - After - Finally with all of these bits and pieces dealt with, and a suitable automotive rubber 'O' ring sourced to fit the pump/filler cap joint; the first attempt at a firing up in decades : OK, no leaks , but a new jet might be in order ... Better! So what do we have now: The modern pan ring is a functional substitute for the exceptionally rare, massive, original. The relative heights of the burner and leg tops makes a ring essential. All in all though, a reasonably presentable and usable classic. This was it in use for a coffee even mid-way through the renovation. Meanwhile those few old components that were not able to be actively used are being retained for posterity.