I've had children's play sets before china & silver plate & a beautiful sterling set on a tray, but never some of the pieces in your collection. Looks like silver plate to me, if there are no marks, I doubt they are sterling. In the photos some of them almost look like they could be pewter. Which would buff up nicely.
One mistake people make is just trying to clean silver with polish before actually getting all the oils off first. Wash the pieces in hot soapy water & if they are still not coming clean, use a bit of TSP, but rinse well after.
Beautiful.... can't help you with value, I would have to do lots of research as I haven't had anything like this for years. GG