With the latest version of Jessie, I left everything as standard and added the following to dhcpcd.conf:
interface wlan0 metric 100
interface eth0 metric 300 static ip_address=192.168.1.69/24 static routers=192.168.1.1 static domain_name_servers=192.168.1.1
I can now access the web management interface on a non-DHCP switch connected to eth0. I can, simultaneously, access the Internet from the Pi, or more specific to my use case, use Teamviewer to remote access the Pi from a PC.
If I reboot the Pi, it all works. If I turn WiFi off then back on, it all works. If I unplug the cable to eth0 then plug back in, it all works.
It took me a while to work through the many posts proffering advice, a lot of time and a lot of Pi rebuilds. I hope this helps someone! :O)