Not really up on who all made them, but of what I have seen most of the Better grade guns had the lever on the right while some lower grade ones put it on the left. I have a W Richards with the left lever. This gun is Birmingham proofed but is neither a Westley nor William, most likely built by Clabrough. As skeettx said, "Condition is Everything". Unfortunately, mine is in no condition to use.
Just from handling it, I feel I would like it, & also feel I would much prefer the left lever. I have not tried a right lever for comparison though. I do not feel it would have a significant advantage over the top lever, nor a significant disadvantage either. I "Think" I would prefer either the left or top lever over a right lever, but again have not tried the right one.
