As for the 1941, there is only 1 coin. It is a US 1970-S proof quarter struck on an 80% silver Canadian 1941 quarter. Technically not an error since it was manufactured by mint workers intentionally. But someone owns it and I am sure they paid a great deal for it. To me it is an illegal coin that should be confiscated and destroyed. If it were a business strike coin and the 1941 somehow got in with the quarter planchets accidentally, and entered and was discovered in circulation, then to me it would be an error. The fact it was a proof coin seems no question that chicanery and at least 1 clandestine mint worker was involved in this crime.
@Wilddavy, I'd highly suggest that you read these articles and save yourself the time and money. What you have is an average quarter that has seen 50 years of circulation contrary to the delusions of get quick rich videos and click bait articles. https://coinweek.com/us-coins/coinw...coins-you-wont-find-under-your-couch-cushion/ https://www.snopes.com/fact-check/1970-quarter-ebay-canada/