I realise my subject heading isn’t at all enlightening but I couldn’t think what else to write.
My question is - is it possible to import an existing project into another existing project in order to split the screen for editing purposes?
I’ve a sense that it isn’t possible but as Scrivener offers a wonderful number of various options I’d like to be proved wrong.
Any replies would be much appreciated - even if they’re negative 
thanks,
martin.
You can drag & drop docs or whole folders of docs from one project to another. This initiates a copy operation.
Once you have the folder of your old manuscript copied over, you can split the editor and have new doc in one side and old doc in the other side. Scrivenings mode may also be useful here, if the two projects are not parallel in how they break down into docs.
Does this achieve what you are looking for?
gr
Yes, that’s exactly what I want to do. Much thanks for your prompt and helpful response 
martin
The File/Import/Scrivener Project... menu command offers the most complete way of fully importing one project into another. Drag and drop will work best when you only want some parts brought in.
Also note that projects can be fairly easily integrated with one another, which is a great option when several projects may all want to pool their research together, or when there is so much research that it makes keeping the project backed up a slow process.
Thank you. Yes, I used the file/import/scrivener project command which did exactly what I wanted it to do. Now I have no more reasons to delay and dither over being creative with my writing project
Thanks again for your suggestion.
m.