I know it may be a shock but I don't have multiple examples of each year to make a CSI quality statement....but this is my info from a look at a lineup of 303s.
There appears to be three phases of the Buck factory production 303 knives. The first rounded swedge as per photo above of older knife, lasted from 1986 to 95,96 and 97 when the tops were flat ground with no swedge, then back to swedge for 98 and 99. In 2000 the sharp swedge era started. So it looks like any 303 - 1986 thru 94 plus 98 and 99 should meet your desires for the rounded swedge as per photo above.
Also remember, production knives are production knives and sometimes if hand polishing occurs on the the knife variances may occur. But, I don't think the process for the recent era 303s allows too much hand polishing variance .
Try to find a nice 303 with the BUCK escutcheon and try the 425M steel in those era blades. 86,87,88 and 89.
300Bucks