[MFAFF]

Lots of well known Porsche business around Oxford....
Autofarm (moving early 2019 to Boxengasse near Bicester)
Tuthill Porsche (closer to Banbury)
Neil Bainbridge Motorsport.

All very friendly places... often happy to have a conversation with enthusiasts.... and show them around their workshops etc if they have time..

Also nearby is the Porsche Experience at the Silverstone GP circuit.

The 'local F1' teams have relatively little public access museums etc...as far as I know... perhaps a glimpse of some trophies and a few chassis.. however most are behind a security barrier. It might be worth e-mailing in advance. Local teams are Force India at Silverstone, AMG Mercedes in Brackley (near Silverstone) and Red Bull in Milton Keynes.
Willaims are at Grove south of Oxford.

Couple of posters here are in F1 teams.... might want to touch base with them.

Also near Oxford is the Bicester Heritage Centre... Porsche Classic have a little short here and there are a slew of very high end sales showrooms and engineering shops there... well worth going for a Sunday Scramble event (early Sunday am meeting when everything is open) dates for 2019 should be on their website.

Museums close to London are Brooklands....a train ride from Waterloo to find yourself at the world first racing circuit.... loads of historic and more recent cars and planes as well. A day out at least, nothing Porsche there though as it closed before WW2.

In London there is a Porsche Centre on Berkeley Square... near the Bentley/ Bugatti showroom and next to the Rolls Royce one.. slightly surreal.
McLaren are at One Hyde Park in Knightsbridge.
HR Owen are near South Kensington tube station... and Fiskens are round the corner in Queens Gate Mews. They often have some rather special classic 911s in stock.

Further afield its worth checking dates of the Goodwood Breakfast meeting in the spring, monthly 'themed' breakfast based events on track. Normally a large number of interesting cars turn up... not always linked to the theme.

Might help a bit....