Does anyone make a PE set for Trumpeter 1/700 1915 Warspite? I did a search of the usual suspects but found nothing interesting. Or do I have to go with generic RN railing, stairs, etc? Could I use WEM's WWl Queen E class PE set? Or parts of it?

I have neither model or PE set but I would say yes.
The QE class had very few differences in their first years, actually quite difficult to identify them on pics.

Greetings from snowy Shanghai

Pit Road have issued the kit with PE. I would give it a little time mate as the kit has not been out very long. Patience Grasshopper..

Ratz!! Now I'll have to put it back in the box. I've already started a bit of it. It definitely looks better than Trumpeter's previous models, but something looks not quite right with the main gun's muzzle's, and there seems to be a little too much tolerance between the main decks and hull fit. It would be a nice touch if Trumpeter started boring out the muzzles of the main guns. I hate having to drill them out myself and having the hole slightly off-center.