i found this layin on the ground at a junk yard about 30 years ago. didnt really know what it was, but thought it was cool so home it went. now, i want to use it on a flathead ford, i think they were an oil bath, but there is nothing else inside like a screen or what ever. so, just oil? thanks, skip
O'Brien truckers sales a reproduction that uses a replaceable air cleaner, I'm sure someone has one and can tell you what air filler will work with a old oil bath.
Don't use any oil in that air cleaner as it will be nothing but trouble. K&N makes an air filter that fits perfectly inside that air cleaner. I don't have any part numbers but I can help you out with measurements. The air filter is round, not oval and measures 2 inches in height, 3 3/4 inches in overall width, 2 3/4 inches inside width, and the filter is 1/2 inch thick. Once the air cleaner is screwed back together and the air filter in place, the filter is then firmly held in place and you should be in business.
the K&N sounds like a good idea. there are some cast in, ah...like little dams, or baffles, i assume to keep the oil from flowing around too violently, so they would have to be ground out for any modern filter. i hate to wreck original shit, but i suppose thats what most folks would do.
Mine (O'Brien Truckers) are modified inside to take a replaceable washable element that filters much better than the ancient oil bath method. I don't think you can put a 2" tall round element in a stock one with the stock oil baffles in the base. Also, the "windows" around the top to let the air in are 1/8" taller on mine to let more air in. They were dyno tested on a 390 FE Ford motor a long time ago and worked better than "open" ones. There are pictures of the insides here: https://www.obrientruckers.com/ecom/product_images/239/2591/#ProductImages