Chipmunk Pt No query

Hi all

As some of you may be aware, I’m currently restoring (slowly) the cockpit section of Chipmunk WP927. I’ve made a lot of progress but I’m trying to pin down the Pt No of the lower former at Frame 7 as this will give me an accurate profile for the lower fuselage skin. The original item was too badly damaged to identify. If anyone has a clue as to what this Pt No should be it may help me in sourcing a NOS item to benchmark this area. I’ve attached an extract from the repair manual to help with identification.

TIA

John