Re: Window Hatch Locks
I think you should use Polycarbonate plastic (traded under the name Lexan or Markrolon. It’s less brittle and have better impact strength than. Polymethylmethacrylate (PMMA) more known as Plexiglas
See below text from Wikipedia
Polycarbonate is a durable material. Although it has high impact-resistance, it has low scratch-resistance and so a hard coating is applied to polycarbonate eyewear lenses and polycarbonate exterior automotive components. The characteristics of polycarbonate are quite like those of polymethyl methacrylate (PMMA, acrylic), but polycarbonate is stronger and usable over a greater temperature range. Polycarbonate is highly transparent to visible light, with better light transmission than many kinds of glass.
Polycarbonate has a glass transition temperature of about 147 °C (297 °F), so it softens gradually above this point and flows above about 155 °C (311 °F). Tools must be held at high temperatures, generally above 80 °C (176 °F) to make strain- and stress-free products. Low molecular mass grades are easier to mold than higher grades, but their strength is lower as a result. The toughest grades have the highest molecular mass, but are much more difficult to process.
Unlike most thermoplastics, polycarbonate can undergo large plastic deformations without cracking or breaking. As a result, it can be processed and formed at room temperature using sheet metal techniques, such as bending on a brake. Even for sharp angle bends with a tight radius, heating may not be necessary. This makes it valuable in prototyping applications where transparent or electrically non-conductive parts are needed, which cannot be made from sheet metal. Note that PMMA/Plexiglas, which is similar in appearance to polycarbonate, is brittle and cannot be bent at room temperature.
It's more info on both Lexan and Plexiglas on Wikipedia,
I worked once in Lexan and it was not that easy for a not so handy man, it melted when sawing and the cut was not that tidy, but for a handy man it should be doable.
Paul on S/Y Kerpa