I got this lantern from @MarkC. (See here for more images of original condition Hasag 351L in steel ) In spite of its looks, the overall condition was quite good and I was pleased to find that the inside of the steel tank was free of rust and looked quite clean, never the less, it was washed out with cleaner / degreaser. The tank was cleaned back to bright metal in the sandblaster and sprayed with etch primer, it would later receive a coat of PlastiKote Garden Green. The support collar was cleaned with fine wire wool, polished with Autosol and finished with High Temperature clear lacquer. The frame and inner hood were sandblasted and painted with VHT silver paint which was baked on at 200 degrees C for 30 minutes. All other steel parts were cleaned with a wire wheel in my Dremel. The filler cap got a new seal, the needle control got new graphite packing, a new Petromax 250cp nozzle replaced the broken original one and a repro Hasag glass (122mm x 122mm) was ordered from Hytta.de The vapouriser was a different story, it was a little bent but the real problem was that the threads at the top end and also on the jet, were destroyed. I believe they were originally M6 X 1.0 as found on two post war in my collection – could this be a clue as to the lanterns age ? After cutting off the upstand above the heatsink, Stu @loco7lamp machined and silver soldered in place, a new upstand which was threaded M5 x 0.9 to match one of my spare Hasag jets. Notice how concave the jet is. With everything re-assembled, a dunk test proved there were no leaks and a test burn gave a nice clean flame. So with a 500cp Peerless mantle fitted it was time for lighting. Very bright but I had to use the cleaning needle every 15 or 20 minutes and I began to wonder if the tank and vapouriser were as clean as I thought they were, so I emptied the tank and rinsed with fresh kero. One and a half tankfuls of clean kero later and still having to use the needle every 20 minutes or so, I decided something must be done. The air gap is fixed but I still had a couple of options, I could have raised the mixing tube by fitting a washer underneath this flange But after comparing with other Hasag jets, I decided to shorten the new jet by reducing the concave. Would 1mm make much difference ? I like to think that it does, since shortening the jet, I burned a full (1ltr.) tank and only had to use the needle twice. It may be just that the lantern has finally settled down, Ether way, I'm happy with it. Henry. .