First, ensure your firearm is unloaded. Remove the magazine, open the action and check the chamber.
Flip the safety off, with the action still opened, pull and hold the trigger back, this will allow the bolt to slide out. The bolt handle and bolt face are two different pieces of metal. They can come apart by simply spinning one until a small ball bearing falls out of place allowing the two to come free.
Next, turn the shotgun over and inspect the bottom of the firearm. There are a few small screws that retain the plastic trigger guard, I don't recommend removing the trigger guard unless necessary.
In the middle of the stock, near the magazine well there should be one large screw. Using the appropriate screwdriver, remove this screw. Once this is done it will allow the receiver to fall from the stock.
Clean.
60's-80's
Mossberg bolt-action shotguns rarely sell for more than $140.
185 d Model 20 ga Mossberg Whats the Value
100-150.
Mossberg model 346 KB
A Westernfield M72 (actually a M72C) is a Mossberg Model 472. You might try http://www.krausebooks.com/category/firearms_knives for disassembly instructions for the Mossberg 472 in the Gun Digest Sporting Rifle Assembly/Disassembly book.
the mossberg 185 does not have a serial number, it is out of the time period where serial numbers were not forced to be used
If in good condition Yes. I have a Mossberg Model 185 and 190 and squirrel hunt with them all the time.
about $100
mossberg 20gauge shotgun mod 185
205
50-150 USD or so