Back in 1995 the BBC recorded dramatisations of two of Georgette Heyer's novels for the Radio 4 Playhouse slot - 90 minute single dramas. One of those two, Friday's Child, was rebroadcast by BBC7 at the weekend, and is available on their Listen Again service until next Friday.
The production stars Elli Garnett as Hero Wantage, and James Frain (Paul Raines in series 4 of 24) as Sherry. There are a few well-known names among the minor characters. Simon Russell Beale (a brilliant Shakespearean actor whom I saw a few years back as Richard III) plays Mr Tarleton, the late Mary Wimbush (Julia Pargeter to fans of The Archers) plays Lady Saltash and Julian Rhind-Tutt (Dr "Mac" Macartney from Green Wing) plays Ferdy Fakenham brilliantly.
All in all, well worth 90 minutes of your time.
The other Playhouse production from 1995 was Faro's Daughter. I do not know whether this has been rebroadcast, or will be soon. It stars Sylvestra Le Touzel (Fanny Price from the 1983 BBC Mansfield Park) and Nathaniel Parker (Harold Skimpole in the recent BBC Bleak House) as Deb Grantham and Max Ravenscar. The BBC also recorded Regency Buck in 1986, with Elizabeth Proud as Judith Taverner, and Steve Hodson as Lord Worth. Going back even further, to 1974, they recorded The Toll Gate, but I do not know who played what part in that.
Sadly Radio 4 no longer supports a slot for 90 minute dramas. The World Service has moved away from any sort of drama, and BBC7 commissions almost nothing new. That leaves only Radio 3 in a position to broadcast any further full-length productions like these. I fear that we will wait a long time before any more of Heyer's books are adapted for the radio in this way.