Oops, let me clarify:
The HS-123 is the old Ertl injection kit re-released by AMtech with an updated Resin interior by Black Box and new, unspatted, injection landing gear.
Sorry for any confusion.
To scribe I used two methods:
1) Triangular file, there is a how-to on www.spasticforplastic.com .
2) Back side of #11 blade.
Both are pretty easy and I haven't decided which I prefer.
I cut the resin parts from their molding blocks with the back of the #11 blade also and it was very effective and quick. At first I was pressing too hard and broke a couple parts (easily repaired with super glue) before I got the hang of it.