The cat is responsible for the sideplate error?. Previously posted the procedure for making a sideplate that "looks like it belongs" in the sideplate panel. Granted some original builders used a sideplate as a 2 hole washer which didn't enhance the LR at all, but these are not to be copied.
The sideplate and its location in the sideplate panel outline is an important aesthetic feature of a LR....afterall, it's opposite the lock side and when shown, should display a certain appeal and also the artistry of the builder.....Fred