You would have to do better pictures to even guess what you have.
Regarding TGs, while a Kar.98a TG will not fit on a Gewehr98 or Kar.98k, the TG off a Gewehr98 or Kar.98k should be interchangeable, more or less. The Gewehr98 will have a hole for the quick release so you can put the sling in parade position but otherwise they are generally they same. Your TG doesn't look like a Kar.98a TG, but either way the floorplate should fit on any German TG, - the floorplate for the Kar.98k is the same as for the Gewehr98 or Kar.98a or b.