These work very well also.I want to replace all my caps with the vent hole on the side to the new style that has the 4 vents in the cap threads. Just for safety. I do have some gaskets for the 3 piece caps, but they don't seem like it fits like the original.
COVID has made them pretty much unobtainable...
No. 3 Cap Seals for Coleman 1-Piece Filler Caps
No. 3 Filler Cap Gasket for Coleman Lanterns and Stoves (Most Post-1970) Qty: 10 pack. Manufacturer: The E.J. Basnett Company No. 3 Filler Cap Seals for white gas and kerosene lanterns, stoves and heaters. (1 pack of 10 seals) These will fit the following Coleman Lanterns: 200b, 201, 220/228...
www.ejbasnett.com
You might have to start buying used lanterns/stoves to find the caps you desire...Be careful!