I feel like Sherlock Holmes tracking down a mystery!
Thanks for the extra photos. So, here is what I see and Bruno et al feel free to correct me. First brass grommets in the tschapka holes suggests to me that original manufacturing was brass fittings. If it were a true M15 these grommets would be steel. Hopefully, I am not seeing things and the grommets are brass?? The inside pics of the side posts look good, prongs are tight and tin washers look proper. The brass trim looks original to me, proper patina and typical wrinkles from the visor expanding and contracting.
The tschapka M15 plate looks original, the wire loops are correct gauge, loops were soldered on and then plate was painted so solder is painted too.
I believe the silver Garde star is a repro, it is also too large for this plate, and does not belong. In 40 years of collecting, I have never seen an M15 tschapka plate with proper M15 small star. The ones I have seen have the slots but no star. James and I bought tschapka plates at the last SOS, never issued NOS, straight from the factory, no stars and solder is painted.
Last, the M15 Dragoon style wappen (helmet plate). The right hand loop is original, proper and solder is painted. The left loop is the correct gauge but I believe it was a period repair or add on. The solder is puddled as it should be and the 100 year patina looks good but no paint. No big deal in my opinion. I believe that old time soldering irons were used on these fittings so solder is always “puddled”. If I am mistaken in my analysis, above please comment.