Hmm. Post a photo or three and I'll see what I can tell you about your gun. If you'd like, you can PM me the serial number, too. A 7 lb 10 gauge could be interesting, with good stock dimensions and light loads.
That 28 gauge has been waiting for engraving for a long time.
There was a guy who used to call about 10 gauge Darnes and wanted one in the worst way. I actually had Hervé call him and tell him "no can do".
My own opinion, and it is free, so it is worth what you paid, is that a light 12 or a 16 Darne R model is about where the guns become very useful. I am unimpressed with V or P models, I don't care for the way they snap open, and they are often (not always, but often) simply too light, especially the 12s. I own too many guns, but, out of my little collection, the Darne R10 is about the closest thing I have to a perfect upland gun. It fits, it shoots where I am pointing, is has a sling, it is light, and the perfect-for-me stock dimensions keep the recoil tolerable. In my collection, lethality is all that really matters, and the only gun I own that compares is a lowly Remington model 17B. I do not shoot either gun especially well on any clays course. I don't know why that is, and mostly don't care.
Gypsy, the gender confused English Setter, is 13, and this will perhaps be her last season-I said that last year too, however. The sling will be handy again, I'm sure.

Best,
Ted