Big Al Whittle, I think this is the programme your sister might be referring to:

Silver by Jonathan Smith

On BBC Radio 4 Extra 01.00 Sunday 2nd February


"When WE Henley, the one-legged Gloucestershire poet and eccentric, visited Edinburgh for an operation in 1874, he struck up an immediate and robust friendship with the more effete novelist RL Stevenson.

It was a friendship that was to survive many storms - including Stevenson's thinly disguised portrait of Henley as Long John Silver in ‘Treasure Island’.

Starring Bill Paterson and John Franklyn-Robbin.

Written by Jonathan Smith.

Robert Louis Stevenson .... Bill Paterson
W E Henley .... John Franklyn-Robbins
Fanny .... Maureen O'Brien
Katherine .... Joanne Mackie
Joseph Lister .... Bill Wallis
Leslie Stephen .... Peter Copley
Sister .... Eva Stuart
Nurse .... Marcia King
Lloyd .... John Bolton

Director: Shaun McLoughlin

First broadcast on BBC Radio 4 in May 1989."