For many years, some lower-tier Buffet clarinets were made by W. Schreiber in Germany. I don't know for sure which models were made by them when; that said, that looks like a Schreiber serial number.
Schreiber serial numbers reached 200000 around 1980 according to my notes, and extrapolating based on the other extremely limited data I have would put your instrument in 1982. I believe it was 1983 when B-C did away with the Evette name and rebranded this model the Buffet E-11, so you might have one of the last ones so named. Schrieber does have production records that they can look up, so you could contact them to get a precise date of manufacture.
I have a 1977 Buffet price list that shows the Evette Master Model as having nickel-plated keywork. From the closeup in the third picture above, it looks like nickel plating to me. I've never tried a silver polishing cloth on nickel, but using Flitz it too turns the cloth black. If the keywork was tarnished a dull gray before polishing, it's nickel. (And that isn't a knock against it - nickel plating is more durable and requires less maintenance. The only tangible benefit of silver plate is to someone with a nickel allergy.)
Having "Master Model" only on the upper joint is how they were - the upper joint is the only one with enough space to have it in addition to the Evette marking.
Schreiber serial numbers reached 200000 around 1980 according to my notes, and extrapolating based on the other extremely limited data I have would put your instrument in 1982. I believe it was 1983 when B-C did away with the Evette name and rebranded this model the Buffet E-11, so you might have one of the last ones so named. Schrieber does have production records that they can look up, so you could contact them to get a precise date of manufacture.
I have a 1977 Buffet price list that shows the Evette Master Model as having nickel-plated keywork. From the closeup in the third picture above, it looks like nickel plating to me. I've never tried a silver polishing cloth on nickel, but using Flitz it too turns the cloth black. If the keywork was tarnished a dull gray before polishing, it's nickel. (And that isn't a knock against it - nickel plating is more durable and requires less maintenance. The only tangible benefit of silver plate is to someone with a nickel allergy.)
Having "Master Model" only on the upper joint is how they were - the upper joint is the only one with enough space to have it in addition to the Evette marking.