The A-Bolt was not in the product line in 1968. What you most likely are inquiring about is a High Power or BBR. You may also want to qualify the term "mint condition". Firearms in mint condition will be unfired, in the box with all factory accessories, and have absolutely no blemishes.
There are many things to consider. Age, condition, scope... Say $3-600.
why do you have one for sale?
Need model info and condition
We need the model and condition.
The exact value of a Belgium Browning T-bolt is actually dependent upon a number of factors. Some of these factors would be the age and condition.
with these fine made Belgium shotguns,condition is everything in the value of your Browning Sweet Sixteen shotgun which was made in Belgium in the year 1957.They can be worth between 300-1,200 dollars if the original condition is quite prevalent and the bore is in excellent condition.
$400-$500 in excellent condition.
50-350 usd
400 or so
500 USD or so
50-575 usd
250-550 dollars depending on condition and a good bore.