Nothing ever HAS to be replaced but considering the fact the car is 64 years old I think it would be a good idea if you want to have a fully restored, nice car, you don't want your hard work resting on a 64 year old peice of timber now do you?
I have a37 pontiac that I plan on leaving pretty close to original.It still has a wood shelf behind the seat,also the wood frame of the seatis still pretty stout. Check the wood to see if its still good or not .Its pretty easy to determine.Then decide if you want to keep it or not.
I have a 34chev 5 window coupe and the wood was really great, except for the top bows. I talked to a man who knew his stuff about wood and he said to use boiled linseed oil on it . I did and it really rejevenated the wood. Just because the wood is old doesn't mean you can't use it, unless it is rotten, and than of course it has to be replaced. I soaked the wood as much as I could and it really soaked up the linseed oil. It dried to a clear finish and has been holding my car together for 20 years. There are people who make reproduction wood for this car but they all have to be shaped to fit , just like they did in the factory. I got the top bows from them and had to do very little shapeing to make them work. I had a fellow rodder tell me to replace it with sq. tubing and I tried but it was to hard to get the shape I wanted. I was going to make my own bows but found out that I couldn't use just any piece of wood so I bought it and was glad I did.I also had a 35 chev truck but I wasn't so lucky with the wood in it. The door wood was pretty well rotten so I tried to fix it and it proved to beyond my skills so I sold it to a guy who was a finish carpenter and it turned out really nice. I can't find the catalog for the wood but am looking ,hope to post this info soon. Good luck with the chev!