Renewing your licence at 70 is OK unless you are a second class citizen without a passport. Then it all gets a bit blurry.
The basic requirements are an original birth certificate, plus a signed declaration from someone who can vouch its you, with a photo licence of their own, on the back of your mugshot, plus evidence of entitlement to state pension. This worked for MrsW a year ago.
This year, for me they sent everything back, along with a letter which listed evidence required, which is not evident on the forms. So they wanted P45, P60, and Bank statement showing receipt of state pension. They also got a snotty letter.
It's all a bit stupid, and clearly the jobsworths are generating work from pedantry.