I have to say that 2 local (professional) luthiers close to me both refused to refinish a Warwick that I had (SSI waxed) as there was no guarantee you could leech all of the oil/wax out and if you didn't then it could react badly with the paint causing flaking etc.
If you are prepared to sand/strip back several mm of wood from the front and back it may work but they indicated that the wax/oil if applied regularly penetrates quite deep, especially on an old bass.
One final question is your bass a wax finish from new or possibly one of the coated ones which some people mistakenly wax?
Good luck either way.