@O Gauge Jim, Thanks for your response - it explains your high failure rate. I test my classic transformer breakers to Lionel's published specifications and do restorations for the purist, but will deviate with newer internal breakers, whistle diodes, LEDs and such upon request.
For a test of a stock 1033, a 15 amp draw should trip the internal breaker in 9 to 35 seconds. We both agree, that while this protects the transformer, it is still recommended to have curated external protection on all transformer channels, classic or modern.
BTW, I am in Western NY State.