I agree with Jan and partially with J Phillip. This was an original M43 tunic at one time and converted to the M44 style. I believe the conversion was done either in the field or postwar but it was never reconditioned in any type of facility. Here are my beliefs about this tunic:
1. Collar tabs are nice original and appears to be nice original application
2. Breast eagle has been replaced. Great wear on the eagle absolutely no wear on the thread that it is sewn with.
3. Handsewn button holes.
4. Replaced shoulder boards. Expected.
5. Waistband is incorrectly emplaced on the tunic by a tailors standpoint. There is no ease of the body in to the waistband. It is just body sewn to waistband. Compare that to known original pieces.
6. Lining attachment attachment to the waist band again improperly tailored. A raw edge of a rayon material would not be left like this. It would have been folded under.
7. Waistband attachment . Absolutely mint thread used. No wear what so ever.
AT best, IMHO, this tunic was a POW piece that a POW converted to try and make a ragged tunic appear to some uniform standard. Most likely it was done postwar by an individual to make something out of a ragged M43 tunic. This conversion was not done in a refurbishing point just by looking at the tailoring skill used.