Switch S 202 threshold

Hello guys, I think, with my S 202 (Mercedes C 180 T, year 2000) something should be done on the thresholdrs (I trivialize again biting ;-)) ). Ideally change completely. Of course with such an old car come first always the “shit-but-way-the-old-kiss-answers”. But I don’t want to do that. I want to drive the car for a few more years (have put in a lot lately) and would now also take a few euros in the hand to get the ground some more tüv-f My idea: is it possible to simply cut out the sleepers and the adjacent ground, and simply weld in from a well-preserved “donor”? If so, where do you get a well-preserved donor and who would be able to do such a thing in the southern upper Allgäu (around about 200 km)? So I am looking for someone who has a desire and time for this. Please only serious answers. OmG I have heard many times enough. I only post pictures when someone has “bitten”. ;-)) VG, Sven