I had a 602 with the set trigger . I also had the same problem as you , I bought it used and it didn't come with the standard trigger . You don't have to set the trigger , unset ,it has a bit of take up before firing , but it's usable . When hunting in heavy timber , close range , or on cold days , and it get's cold here , I used the unset trigger .You have to push the trigger forward to set it . After I became used to both set and unset weights , I used it with no issues . They really are great old rifles , I regret selling mine , but it was to a good friend who had to have it . He still taunts me with it to this day , maybe he's not such a good friend after all lol .
You can find a standard trigger , they come up for sale every now and then . I had the opportunity to buy one for mine , but by that point , I'd become accustomed to the set trigger and didn't bother . If it were me , I wouldn't let the lack of a standard trigger stop me from buying it ......... but I'm a rifle slut of the worst order . Let us know how it works out .
AB