I have a Husqvarna LGT2654 with the above Briggs engine. Just noticed I have an oil leak somewhere up in engine above stopcock for draining oil. Could this be valve cover(s) leaking? How big of a job is it to repair this for a novice DIY-er? Thanks for the help!

Hi,
More than likely it is the sump(pan) gasket. It involves pulling the engine from the frame, inverting it, removing the sump, cleaning the old gasket from the surfaces and replacing it.
Peace,
Clarke