K frame dating
Any following letters are modifications to (variants of) the base gun.Note that most series also have variants that are not differentiated by a letter code change.Newer pistols have a model name or number, sometimes with a type suffix, clearly on the sides of the gun. "Firestar Plus") are on the slide and any listed model numbers are on the right side of the frame above the grip panels. The Megastar, for example, is the Model 50, but is [more or less] invariably sold as the "Model Megastar." All the modern pistols have model numbers instead of letters, starting with 28.I have no idea what happened to the first 27 or to many of the numbers in between.
Patronen '08 is a way of saying "the cartridges that fit in the model 1908 pistol." The Pistol '08 is the Luger, and more recently the cartridge that fits it is called the 9 mm Luger, or Parabellum.Some are clearly also just chosen for marketing needs, like the .45 ACP caliber Firestar M45. The Firestar Plus is the M243, where adding 200 to the M43 must mean "super version" or something to the Star engineering department.Similarly, the M105 was an alloy predecessor to the M205 plastic framed Ultrastar.For further information, please find below a leaflet and two example reports for down load.One on sampling of live trees on the Ancient Oak at Lullingstone Park and one on dating a timber-frame building at The Rock Inn, Chiddingstone.