These brass cars were manufactured in Korea by Mi Lim. I'm not sure when they came out, but my guess is the 1990s. At some point Shoreham Shops was sold and renamed Railway Classics (who then continued to offer these cars for a time). AFAIK, Railway Classics is now out of the N scale passenger car biz.
All cars come with window glazing, Micro-Trains couplers and rubber diaphragms. There are three different sets -
Set 1 - Baggage-Mail, Baggage, Coach, Vista-Dome Coach, Slumbercoach
Set 2 - Vista-Dome Dorm Lounge, 10-6 Sleeper, Diner, 5-5 Sleeper, Vista-Dome Observation
Set 3 - Coach, Slumbercoach, 10-6 Sleeper, 10-5 Sleeper