I am looking for a replacement for a VN45MR stylus.
Yes, there is another stylus. The VN35MR fits the V15-IV body. The VN35MR does not have the dynamic stabilizer (brush) of the VN45MR, and the frequency response will be brighter when used with the V15-IV body.
To upgrade to a new cartridge similar to the V15-IV, consider the M97xE.