People have a lot of different definitions of "excellent", so any internet answer will be speculative.
Unfortunately, the 42 and the 49 are not terribly valuable. Even in great shape you can expect from $250 - $400 depending on your area. It is however a fine old shotgun to have hanging on the wall, and a nice conversation piece.
Your Marlin model 336 in the condition that you describe will bring between 300-375 dollars.
The Marlin model 94 32-20 rifle is valued at $480 in good condition. In excellent condition, it is valued at $750.
The value of a Marlin Cal bolt action model 187 gun depends on its condition. This gun in excellent condition is worth between 90.00 and 135.00 as of 2014.
The Marlin model 30G serial number 3512 20 gauge shotgun is valued at $350 in good condition. It is valued at $750 in excellent condition.
75-150 dollars.
about $140 depending on the condition
As indicatyed by the model, 1981. Values run right with normal 336 Marlins. In excellent about $250.
Your Marlin model 15YN little buckaroo single shot,which was made in the year 1994 will bring between 80-110 dollars in the condition that you describe.
125
Your Marlin model 989M2 will bring between 75-150 dollars based on how good the condition of your marlin is.
The marlin 1897 lever action 22 is valued at $555 in fair condition. In excellent condition, it is valued at $1,150.
The value of a Marlin model 336 in that condition is 350-400 dollars.