I was a docent at a Hanger for aircraft from WW2 and prior. It wasn't a museum because all of the aircraft flew. Then it got killed by covid, but I digress. We researched all the aircraft and delighted in presenting a previously unknown fact about one of the aircraft to our fellow airplane geeks. (Old men with not much else to do.) What became part of the presentation for our Spit was that it had wooden props so they would break off during a belly landing and save at least some of the engine. Supposedly, the props were milled on lathes purchased from Germany before the war.
Someone mentioned the cost of a rebuild for a Merlin. During a PE on our Spit our A&P mechanic found metal slivers in the oil. We had to fly two mechanics from RR in England to do an inspection and take the engine off of the aircraft and box it up for shipment to California. This took a week; hotel, car rental, etc. on us. Three months later the engine came back and the Brits returned to install the engine. We didn't have a proper jig so the alignment and installation were done with a fork lift. Funny, it was nothing when I watched it happen, just another day at the office. Now that I write about it was pretty amazing. No one ever gave an official final cost, but the rumor mill produced a figure just North of $500 K.