I often heard that fatigue of metal castings was fairly common in earlier kits. Yet, I’ve had no such experience with the many old cast metal freight cars that I own. So, I was surprised to find that the cast metal mainframe of a Rivarossi manufactured between 1974 and 1980 had disintegrated. I don’t know enough about the process or type of metal used in these casting and what makes one lot of castings more susceptible to cracking than another. I own several other Rivarossi (AHM) locomotives and I find no evidence of failure in those, but I wonder if any other forum members have experienced similar failures with Rivarossi. I always loved the early “Flat Faced” Southern Pacific Cab Forwards (AC-4,5,6) but I just could not see spending $1500 for a brass model, so I didn’t think I would ever own one. Then, several years ago, a friend sold me a Rivarossi AC-11 Cab Forward in pieces for twenty bucks. Here was my opportunity to create a flat faced cab forward with a bit of modification! The original rectangular tender was missing as were other small parts. Soon, I found a Bachmann Vanderbilt tender that was exactly correct for my AC-6 (how lucky can that be). I removed the front of the cab and created a ‘flat’ one from sheet styrene. Then I shaved off many cast-on details and replaced them with brass parts. I was proud of my AC-6 and have enjoyed that loco for about 15 years. Then it happened. Last week I picked up the engine and the rear powered truck fell off! I discovered that the single piece cast frame was beginning to disintegrate and the kingpin holding the rear truck was the first indication. Once I removed the shell I was able to see the extent of the damage. The entire casting is cracking. Unfortunately, that loco has seen at least four configurations over the past thirty years making it nearly impossible to order the correct replacement part. So, I proceeded with a short-term fix. I found a different Rivarossi frame with a cast-on kingpin in my parts drawer and by careful measuring and cutting, was able to remove the kingpin section and mount it in position on the AC-6 using a small screw and lots of epoxy. The original frame also served as an electrical bus, but now, due to metal separation, a wire jumper was added to electrically connect the rear truck to the front. However, this is only a short-term fix. I am now on the lookout for another Rivarossi (AHM) Cab Forward to cannibalize!