Roof vent hatch assembly

[Steve Hogle]

I need to find the whole assembly for the forward roof hatch. Outside mounting flange: 16 3/4 x 23 3/4, inside drop-in flange: 14 3/16 x 21 3/4, roof cut-out hole 14 5/8 x 21 3/4.
Marlo's RV in Santa Rosa doesn't work on any of the old vehicles, but they told me to contact RV DR. George in Sacramento for the old and specialty stuff.
Sent them a request, but not sure if it will come together.

Any thoughts are welcome! Many thanks!!
Steve H