UK citizen returning to UK after 20 years in USA

I am obviously not in the same situation as many of you in this community, but face many of the same questions.

Can anyone offer advice on how to deal with UK pension after living and paying US SS in for 20 years? I worked in the UK for 4 years prior to coming to the US.

Also, I have US 401k plans am need some advice on how to deal with them. Do I keep in the US or cash out?
Regards,
usbrit

You may want to check out www.britishexpats.com in the returning to the UK section. Many have lived in US and Canada for many years and are returning after the age of 50.
Also I believe the US embassy has a Social Security department for whan you are old enough to claim. Make sure you are a US citizen before going back too.