I don’t do a whole lot of scoring, but when I do, I lock some 2 point rule into the chase and use my press. I’ve also tried string scoring, by locking up two lengths of rule separated by 2 point lead and taping a string on the platen so that the string falls between the two rules. Works really well, but a bit trickier to set up.
I have used a carl paper trimmer but now I use a score board I bought off ebay.
Manual table top Professional Scoring Creasing / Creaser Machine – 14¨capacity was the title. And I really like it. It has guides that are not just magnetic – you screw them down with hand screws and it keeps them more stable! I paid around $170usd
And its a one motion score not like the carl which you had to lock down and then run the wheel across.
So far the only annoyance is I wish that it had a little more space to slide the paper in (and for me I wish it was much smaller! it is HUGE!)