A wrap on this drum construction won't make much (if any) difference. Besides, the rest of the kit is wrapped, so all is good. However - caution: If the existing lacquer is fairly thick, the two finishes in combination could produce a slightly more focussed affect, but more importantly, a potential head flesh hoop fit issue that may necessitate a work around.In all honesty... It probably is somewhere
I have little doubt that wrap dampens things a bit. I have no reason to believe that it matters enough to notice on 95% of the ply-shells out there. Lacquer on a Pearl Export magically won't make it sound like a Vision. Wrap a Guru on the other hand... Would it still be a Guru?
Warning! Wrapping a Guru, or even considering the possibility, is an offence punishable by a fate worse than death (namely a week at the buttstrap Eder school of revolving drums followed by another week of "how to patent an existing bearing edge" presentation by a marketing expert!