I've tried various searches but haven't managed to come up with anything I'm confident in. This is a found rose from my in-laws (we think it was already in their yard when they moved in, some 30+ years ago). I've tried to include pictures on any features I thought would be useful so hopefully I haven't missed too many. I would describe its fragrance as strong classic old rose, but I'm not broadly experienced in such things. It's a single-bloomer blooming now for me but I'm thinking it's often a few weeks later.

The flower is maybe 1.5-2" across, very double with a button and eye in the middle which I hadn't noticed on on my inlaws' plant but is very clear on the start I got from them here. The color might not have come across well, but looking at embroidery color tables, it looked closest to DMC 718 (e.g. https://siterepository.s3.amazonaws.com/4207/dmc_718.jpg). You can see on the left that the flower, especially the outer petals, fade as it ages.

It's rather glandular with the oil fragrance being somewhat resinous. This pic of the buds shows that somewhat.

Here is a picture of the hips from last fall. They're maybe a centimeter across. This picture shows off the glandularity well.

Here's the general habit of the bush - largely untended for the past 30 years. Suckers some but not extensively (again, caveat of my lack of experience). It's maybe about 6' tall, but it's on quite a bit of slope so it depends on where you stand.

And since I've seen other mystery-rose ID requests mention leaf-base pictures being handy, here are a couple of that. These also show the difference in thorniness between new growth off old wood (first pic) versus a new cane (second).

Thanks in advance. I look forward to seeing the possibilities that turn up. If any other photos would be helpful, I'll be happy to include them as I'm able.

-Don