Adam: If you chedk out the H12 Registry document, there is quite a bit of detail on this topic. I also hope to post a document shortly on identifying your 12 which will go into this topic as well. Essentially, HMC licensed the Quincy Adams Shipyard to build the 12 in 1943. Between then and 1948, QA built 51 boats. They used the HMC builders plate with hull numbers 2000 - 2050. They were trimmed and planked in mahogany and had the Fisher's Island configuration minus the copper flotation tanks. From 1948 until the early 50's, Cape Cod Shipbuilding built about 34 boats. They were trimmed in mahogany and planked in cedar, as were the HMC boats. However, HMC used butt-blocks when planking and CCSB used full-length planks.
-Steve