Currently, what the available fleet of N scale boxcars, especially earlier boxcars, desperately needs is variety. Wood boxcars (steel underframe, of course) are limited to the Atlas USRA single sheathed and double sheathed versions, and Micro-Trains cars of the same design. Arguably the single biggest thing missing from that era is a 6 panel outside braced/single sheathed (the same thing) 6 panel wood boxcar. It's a pretty generic design, so it could be made lettered for plenty of railroads that had the same or similar cars, and nobody's made a quality one ever, or even any at all in decades, so there's a relatively large unfulfilled market and should sell in reasonable numbers, not just this forum. Whoever makes it could also do what Atlas has done in the past with doors/ends and offer it with either wood or steel ends as well.
If you are talking about ~34-36' boxcars like this Nn3 one here: https://modeltrainmarket.com/cdn/sh...4583-926e-c6b8a7675f0f_2000x.jpg?v=1690536298 (not Nn3 in this case) then I would most likely be in for 3-5 or so, depending on price (I am working on a budget right now).