Would need to see pictures and the serial number
The age of your winchester model 1873 is considerable.The rifle was made by winchester in the year 1885.that is 126 years ago.As to value I would have it looked at by a member of the winchester collectors assoc.or a qualified gun collector who specializes in winchesters.
It sounds like you have a "Yellow Boy" Winchester 66, and is the Fourth Model since it is centerfire. It the serial number is between 149000 and 170101, that proves it. It has a minimum value of $1,000 if it is even in one scraggly, rusted piece (a 10% gun), and could be worth upwards of $9,000 it it has most of the blue, good yellow color, the wood is good, and it shoots good (a 90% gun). You definitely need it appraised by a professional gun appraiser it it is an excellent gun.
Barrel marking, chamber cast.
Xx
Can't be answered as asked.
What's the question? Could you rephrase it?
50-100 USD
50-1500 usd
10-1000 USD depending on the specifics
50-550 usd
You might try here: http://www.coltparts.com/index.html
100-400 or so