Early model E29 Hull Thickness

[HGSail]

I am replacing my old thruhulls with new seacocks. I am making new backing plates out of glass and I was wondering what the hull thickness is under the Sink and Head

Pat
E29
'73
#224
Holy Guacamole

 

[Permenter59]

How did your replacment project go? Am considering the same thing on our e29