There is quite a lot of information regarding "stencil" kits on this site. These were knock off, very cheaply made drum kits by Pearl, Hoshino and Star (which became Tama) and sold under literally hundreds of names of which Coronet was one. These were the kits that were sold in Sears, JC Penney, Montgomery Ward catalogues as well as every music store on the planet. They were the really cheap drums aimed at beginners whose parents did not want to or could not shell out the money for Ludwig, Gretsch, Rogers, Slingerland, etc. The term "stencil" refers to the fact that the three manufacturers would badge these at their customers (the musical instrument distributors) request. Apollo, Crown, Coronet, Royce, Majestic, Zim Gar, etc., became names synonymous with cheap, entry level drums. Of course, some kits were better than others but most were pretty pitiful. These are not at all the same quality drums as what Pearl and Tama eventually started manufacturing in the 70's.
Flash forward 40+ years and it seems that these drums have improved with age. They usually require some work such as dressing or completely recutting bearing edges, possibly finishing the interiors with various oils or other products, and most importantly new heads and better tuning abilities of the owner. Once all of that is done, many drummers find that they actually sound pretty good, especially at lower tunings. They still are not worth much but it does appear that your kit is in really nice condition and well cared for. The greatest monetary value for these kits is in finding a drummer that is looking for your exact kit because it is identical to his/her first kit. The sentimental value will drive the actual value. It happened to me when i found an identical kit to my first one.
