I don't think Hawk has been active since 2004, so there is close to no chance of getting in touch. Your best bet may be to try the people who have already updated Hawk's work: Bonko the Sane and Apex.
Furthermore, I don't think the problem is a missing texture, but rather wrong lighting being applied to the surface - it seems to shine in the night. As I see it, you have three options:
1. (Simplest) Do nothing
- if you apply the NVG overview when looking at the cockpit at night, the problem is not noticeable. I'd guess the same would go for viewing it in daylight. Dusk and dawn would be the most awkward times.
2. (Righteous) Supply a fixed model
- the models are already in MLOD format, so make a fixed copy and provide it in a separate pbo with a config deriving from the originalclass RPT_hwk_C130: hwk_c130 {};
3. (Troublesome) Release your own HWK_C130.pbo
- it's addon- and mod-makers who would most frown upon this, but I consider some of them to be excessively precious about their work. In my opinion, addons should be considered as copyrighted materials, it's just that that copyright must expire eventually and I'd reckon five years to be reasonable. Thereafter, treat it as copy-left and admit whose source material you are (ab)using.