Someone at the Remington Society of America web site could probably help you.
Manufactured 1919
According to the Remington website, there are three possible years for the manufacture of your Remington UMC 380, with a serial number of PA 50795. Those years are 1995, 1968, or 1923.
http://stevespages.com/ipb-remington-51.html
Condition?
Made in 1919. Check the associated link.
Depends on condition, condition, and condition. From $100 to $1,200 LNIB.
Union Metalic Cartridge Co. is a division of Remington UMC purchased Remington Arms Co in 1912 and became Remington Arms UMC.
fair condition 300-400.
Greatly dependent on condition. from $200 to $1,200 for new in the box.
Depends on what you mean. UMC is a brand of ammo made by Remington. UMC = Union Metallic Cartridge By Remington
1912
The value of a Remington UMC 380 PA1827 can vary based on its condition, age, and market demand. Generally, prices for this model range from $200 to $500. For a precise valuation, it's best to consult recent sales data or a firearms appraisal expert. Always ensure compliance with local laws when buying or selling firearms.