It normally takes a bit more information to come close on value. What is the serial number?
A non prefix rifle 1967 - 1969 with a Douglas barrel and vertical rings might bring $1000 - $1200
A 130-0001 - 130 -5000 1970 - 1973/4 would still have first checkering other than the forearm diamond and still have a Douglas match grade barrel. It might bring $800 - $1000 to a knowledgable buyer.
The pre warning rifles might bring $800 or so.
Some people pay a small premium for 1976, 200th Year marked rifle add $50. I have to admit that I for one seldom a premium for 200 Year guns.
I've bought well figured reb pads from the 80s with the Wilson barrel with the "warning for $650 - $850 predicated on just how good the wood was.
I would price newer black pad rifles in that same area.
There is one caviate and that is always WOOD!! Just HOW good the wood is is always the determining factor. I've paid $1000 for #1s of no particular collectability/rarity based soley on the wood.
Contrary to what the web sites seem to indicate by asking price, the 6mm Remington in "B" and "V" are not rare. The "B" was chambered for 33 years 1970 - 2003 not including the 1000 or so made in the non prefix era.
Uno: YOU do NOT need another 6mm!! If you send me the address/seller I can /will gladly save you from yourself. Heck, I only own 4 in 6mm Remington and could always use another, especially with good/great wood. ;-)