i'm having a bit of trouble understanding. do you need the price it sold for back in 1951? or current value?

I had a thought you might try, if its the 1951 value you need, from what I read the model 51 actually didnt come out til 1952 so I would look on ebay and try to find a 1952 sears and roebuck catalog. if its the current value you need I will check with my gun dealer friend see if he knows the value.

ofcourse you do realize current value can vary depending on condition?