migration issue

…or knickers in a twist…..

I have to migrate a site from one server to another.

I have a nifty SQL search and replace and generally have no problem moving sites backward and forward from local to remote and vice-versa.

This installation;

The original has the WordPress at root ,my preferred way of working is to have WordPress in its own directory /wordpress.

So I’ve transferred the database from one install to the other. But I can’t log in because the redirect is not working. Once I login I get a redirect 404

How do I unravel this? I assume (assumption is the mother of all cockups) That I can change directly the site_url and home fields in wp_options in the database but this doesn’t seem to do the trick.

Help please