Will this Lens Mount work with the Canon lenses I have?
YES, It will allow you to mount your FD, or FL, lens's to your PEN E-PL1 but see note below, I can not speak to functionality as I know nothing about the PEN E-PL1.
From the amazon link.
Note: This is a manual adapter, so lens functions that rely on
electronic communication with the camera body (autofocus, AE metering,
image stabilization, etc.) will be disrupted. Set your exposure
manually or meter using your camera's Aperture Priority (stop-down)
mode. If your lens does not have a manual aperture control ring, it
will stop down to its smallest f/stop by default. All pictures are for
illustration purposes only. Actual product may vary slightly due to
ongoing improvements in design.