There are a lot of pics of pressed-back chairs with cane bottoms on the web so this is starting to make sense. I'm fairly handy but have not installed a cane bottom. Looks like maybe I was on the right track with that strip, it's for a cane seat, and I would have to dig it out and use that groove to install a new cane seat, right?

It's going to leave a lot of holes where the replacement seats were nailed on, I'd just have to fill them in I guess. Or sand smooth and leave them as a conversation piece.

Wow, thanks for those instructions! I think I can do that. When I started this thread I really had no idea what to put on this chair and kind of figured out the caning as I went, but I was not sure how to actually install it. Your directions are very clear. I will find a place to get some caning, already have glycerin around and all the tools.

One more question, based on the color of my restained pieces in the second pic, do you think the cane should be left natural or is it possible/advisable to stain it? Seems like it would be very bright and maybe distract from the rest of the chair, but I don't know.

That looks to me like a woven in place cane seat (search for "caning a chair"), not one of the ones where you use pre-woven material and press it in place with a spline. It takes more than a couple of minutes to cane one, but it's not rocket surgery. and is fun to do-- lots of patterns can be created. Here's a link to one of the many instructional pages available.

The press-in-place cane was a later, cheaper way to do it that doesn't stand up nearly as well.

The holes from previous repairs don't bother me near as much as prospects of getting stains out of wood where it was covered by leather seat. I would finish up with stain and clear coat before buying cane. You may have no choice but go back with leather to cover deep black stains. Fine old chair,any known history?

New cane will be light....and cane doesn't take stain well....but does darken with time. the under side of the cane is porous and will take stain....but there is no point in that.
Your new cane will look pretty much like the pictures you found of other similar chairs with caned seats.
Oh and don't forget....as the caning dries it will shrink a bit....so don't worry about minor sags....but also don't make it so tight that when it dries it pulls the spline out of the groove.

I pried the old spline out of the groove and there were still bits of cane under it as you would expect. I don't know how you'd tell if a chair was hand-woven or not, but there are no holes all the way through the seat, only the groove. Given the time I've already put in, I think I'll be using pre-woven just to get it done.

I'm pretty good at cleaning up stained old wood so I'll sand some of the crud off, strip off the finish and stain and see where we're at. If necessary I'll use some wood bleach on it to get it to an even color and go from there. Not expecting miracles, just a decent serviceable chair.

As for the history, I got this chair free while picking up some other furniture for a charity furniture bank I used to run. We'd take broken things if they seemed to have value, or just to be nice to the donor. :-D So I have no idea of its provenance. It's been underfoot for several years, disassembled and partially stripped. BTW on top of the sloppy refinishing and former repairs and loose joints and bad seat, it had candle wax dripped all over it. I do love a basket case sometimes.

A chair with a woven in place cane seat has holes around the seat through which to weave the new caning. Your chair never had that kind of seat.
you probably pick up drunken derelicts on the street and turn them into productive humans too....
Just as a suggestion, it might be easier to re do the seat if you do it after you get the chair put together, unless yoj can find another pair of hands.
Show pictures when it's done.

I guess the pattern of dark spots I was looking at around the edge are actually a dirt shadow rather than filled in holes, I stand corrected. Since it already has a routed groove you should use the spline method.

I'll definitely come back with an after photo! These things can take awhile but eventually...

Thanks for all the help and advice. This place is great.