If you use non detergent oil just save your old oil in jugs ---label them, after about 5 years stop buying new oil except to top off and start using the oldest jug---except for the bottom 1/2 inch of sludge ---I have seen this done, I went to a garage sale and saw all the jugs labeled on the shelf and asked about it.
Actually I have used both oil and filters from cars I have changed oil on, one customer had his oil changed every year on his "modern car" --that he didn't drive much, some years it was only the miles to and from the shop, other years it was 100 miles ---it was just too much for me to waste it, the car that got the used oil outlasted my ownership, I sold it with something like 800,000 miles on it. ----these cars had a dual filter, the housing contained both a "full flow" and a bypass filter.
For our model A the oil change interval needs will be different, much depends on your mixture control, if you run a rich mixture (plugs keep burning black, need a hotter plug, got to keep changing them because they carbon foul, only get 12mpg or even less)---then 500 miles may be too much ----then others who run a thermostat to get the engine up to temp quick, have no problem keeping a stock heat range plug burning clean,drive far enough and fast enough to get the oil hot, get fuel mileage in the 20s and have a good filtering system 2000 miles may be too soon---as has been mentioned oil testing may be the way to know what your real needs are ---yes oil is cheaper than bearings ---but changing too often can cost as much as bearings too
