You could try putting a notice out, if you just put them back that could offend whatever delivered them, and is no guarantee the person can recover them.
I always return things I find when possible, and have been very blessed with lost things being returned to me. I know how devastating it can be to lose something when it was your last bit of money, or something with sentimental value, worth far more than the sum of its parts.
There’s also a metaphysical element, when I started working with the Angel of Lost Things, and that may have led to some novel opportunities for other work I have ongoing. 