I too have a 15-91 that my dh bought for me as a surprise Valentine gift a few years ago. We saw it at a nearby "antique" shop and I drooled a bit too much over it and then said I would not buy it because I had no room for it after downsizing our house. (I know, I know, that never stopped anyone else from buying.) I have only used it a wee bit mostly because it has a small wine fridge sitting on top of it right now and I am pretty sure it needs some rewiring as that all did. It is in an art deco cabinet (desk) that I love and it had a bunch of dodads in the drawers such as a sock darner, flatwork darner, zigzagger with different stitch designs, box of feet, etc. Once we get the kitchen straightened out, I hope to have it available to piece and quilt as I have heard it is great for quilting since you can drop the feed dogs. (I often don't do that though as I get a bit more control with them up but that has been discussed in many other threads.)
DKuehn, thanks for that rewiring link.