LEAKING SKYLIGHT AUTOSLEEPER TRIDENT T4

Hi Guys,
I purchased a very clean 1991 T4 Trident with a leak in the skylight.

My intention is to replace it, as there was no name on it I took the measurements and ordered an F395 MPK complete rooflight with flyscreen from ishop247 with a couple of tubes of sikaflex. Were these Fiamma made along with the awnings in 91?

https://www.ishop247.co.uk/f395-mpk-complete-rooflight-with-flyscreen-and-blind-40-x-40-ivory.html

Has anybody done this before as any advice would be warmly welcomed.

Well for those that want to do it, I started at 9am and finished the removal of the old one, which had been fitted by AS originally to a high standard and to ty and find the screws that went up from inside was a real pain as they then encapsulated them level with the plastic so practically invisible.
6 x screws which I kept because the replacement as stated above took the old screws direct.
No screws supplied with it.
Sikaflex all round the beading lips on the top and it dropped into the hole after lots of cleaning the old silicone off. Screwed up the mosquito blind and finished by 11am.
Well recommended to anyone wanting to cure that annoying leak. Measurements crucial as there are lots of vents on offer out there. The T4 for reference used 40x40 ones which this one was.......good luck.