OK you narrowed it to the left side now you just have to figure out where its coming from. NOT something we can do online. Shifters are notorius leak points, also any where a hose or wire goes INTO the motor, and breathers. Gaskets fail for a variety of reasons, especially from disuse. considering this is only a 5 year old bike with ONLY 1700 miles on it, that may be the problem, it spent most of its life PARKED. Clean it and monitor till you find the source.
93 VT1100C Sleeper, VH Exhaust, Saddleman Seat, Baby Apes, Metzlers, 2mm sleeved and bored (1150cc),10.5:1 comp, Modified Heads, Valves, Cams, Adjustable Timing, Bored Carbs.