I think Old Grump is in the ball park on values. Both are very nice .22's , I wouldn't mind having either one. If there can only be one, the Remington would be more versatile. As you observed it can use either .22 Short, 22 Long ( kind of rare bird to day ) or .22 Long Rifle. .22 Shorts are nice for close quiet work, the .22 Long Rifle will work for up to dog size animals ( no, I'm not advocating shooting the neighbors dogs , just a comparison ), but like Robert Frost in his poem ( The Road not Taken ) the Mossberg is very accurate and would serve equality well. I also admire your desire on keeping at least one. Good Luck and shoot safe
BTW, thank you for the wonderfull clear pictures, it makes life so much easier