Padded Men's Dotera Jacket

Men's Cotton Padded Doteura (Product from around the 1960s)
Length: Approx. 140cm
Sleeve to center back length: Approx. 65cm
Sleeve length: Approx. 51cm
Only tailored, and no one has worn it for about 50 years.
Stored at home after a new collar was attached.
There is a faint stain on the tip of the right collar (the attached collar). Please check photos 16 and 17.
This is listed as a used item.
Some basting stitches are still in place.
There are folding creases, etc.
Without expert knowledge, I cannot determine if the fabric is pure silk or synthetic fiber.