old E3 Phil & Teds car seat query and cleaning

[Upatnight]

I have a really ancient knackered E3 (over 5 years old at least... probably more) in the shed. I was going to spruce it up and I have a query -
in the basket were a few extras, bumper bar, rainhood etc... and a smallish metal frame of some sort with canvas attached, saying Mountain Buggy. The friend who gave it to me years ago says that she thinks it was a car seat adapter and that the MB adapters fit the E3. It definitely clips onto the frame somehow. But I can't figure out how it works. Anyone heard of this, or know if there are instructions anywhere? I can't find any on the web.
Also, what is the best way to clean the P&T seats and hood - is it just a sponge and soapy water, or does anyone have any better way?
Thanks in advance

The Mountain buggy is a different buggy entirely. Could you be describing the double seat? Zillions of Phil and Teds instructions available to download here.

Mountain buggy instructions. They were made by someone else originallyt, but bought by P&T apparently.

Does it look like tthis? If so, this is part of the mountain buggy plus 1.

It sounds more like the
Mountain Buggy Urban Jungle car seat adaptor More of a spider with spindly legs!

They appear to have been redesigned but I saw one at the P&Ts / MB University last year. I dont know if this helps, but which might help you get an orientation. However I am not sure I would be putting a MB car seat adaptor onto a P&Ts. Do one of the P&T's car seat adaptors not fit instead?

I washed my E3 covers in the washing machine, I've also heard that a pressure washer works a treat. BUT since I washed it the little front triangle soaks up water even with the raincover on and dc3 gets wet feet. This may just be age rather than me washing it though.

Hi, yes Tiggy that is the one! She apparently used it on her P&T, but you are right, I wouldn't want to risk it.
Anyway, at least I know what it is now!! It was bugging me!
Thanks all.