I did the glue and cut to a Ferrari 330 a while back.
Getting away from the clamshell idea is a plus.
This car had a broken guide mount so I wasn't too fussed if I ruined things but in reality I improved it.
I used a front section of an HRS chassis for the new guide mount and glued it in place a little further forward than before.
From memory I didn't use the six (yes six) mounting screws. I did say this was done a while back.