By the mid-80s slamfires were common enough that our armory called the 37s all in. However, I doubt ANY had been fully disassembled for a detailed cleaning ever. We were taught to clean the bore, the bolt where it could be reached, the bolt face & extractor, and to keep the inside portions of the reciever touched by the bolt from getting dry.

They were replaced piecemeal by 870s, S&Ws with a folding stock, and Mossberg 500s. The 870s and Mossbergs were problem-free; the Smiths were unpopular because of the folding stock.