subfolder wordpress install won't resolve at www.url.com/folder

Hi there,
I have been googling and trying things but I can’t seem to resolve my issue.

I had a wordpress install at the root of http://embassygallery.org. I then moved all the wordpress files into a subfolder /egarchive08-15 (I also changed the site and home url in the db to http://embassygallery.org/egarchive08-15 as per instructions).

Almost simultaneously I was moving a local instal of wordpress to this same server, I wanted this instal to live at /wordpress but be accessible at the main URL http://embassygallery.org

After much moving around/ testing (mainly with .htaccess and index.php) I have the wp instance that live at /wordpress viewable at http://embassygallery.org (CORRECT!) (there is currently a holding page for the main page) but although I have had the /egarchive08-15 site accessible (only ever the home page) at times throughout this process, it is now is not coming up at all. The current state is:

– If I go to http://embassygallery.org/egarchive08-15 I get a 404 in the (broken e.g no styles) theme of the egarchive08-15 site I’m trying to resolve.
– At http://embassygallery.org/egarchive08-15/wp-login.php I get a log in screen with no styles. It looks like it’s opening the daschboard but then redirects to a 404 page in the theme of my ‘main’ site.
– If I go to one of the pages http://www.embassygallery.org/egarchive08-15/upcoming I get a 404 in the theme of my ‘main’ site
I’ve tried all sort of configurations of redirects etc and googling. Can anyone help at all? Totally mystified

Any advice would be appreciated!!

Thanks,

Hannnah