I finally got to see The Hound of London, the 1993 TV movie starring Patrick Macnee as Holmes (and making Macnee one of a handful of actors to have played both Holmes and Watson).
First of this is unmistakably a TV movie, and the cheapness of the sets, costumes, etc. is painfully obvious. The stagey nature of the piece, and most of the action literally takes place on the stage in a theatre, makes me wonder if this was originally written for the stage and then adapted to be a TV movie.
(Edit: And in answer to my own question, Wikipedia informs me that yes, the screenplay was derived from a play written by Craig Bowlsby and first performed in September 1987 in Burnaby, British Columbia. The only carryover from the original stage production was Colleen Bignell who played Irene Norton in the play and the much smaller role of the Queen of Bohemia in the film.)
That said, the plot itself is quite good and stages an effective murder mystery with a limited number of players. And it makes several nice references to the canon for the dedicated Sherlockian without forcing them down the viewer's throat.
Macnee never really convinces me as Holmes, although he does capture Holmes' puckish sense of humour quite well (his dry delivery of "My eyesight is not what it was" to the villain toward the end is a delight). However, he is physically wrong for the part, for while he has the height, he is too solidly built. And an early scene where Holmes is seemingly going insane just falls flat. Probably intended as comic relief, it makes the mistake of showing us a crazy Holmes before showing us a sane one. In my opinion, Macnee plays a much better Watson than he does a Holmes.
John Scott-Paget gives us an excellent Watson, and one of the standouts of the production. Colin Skinner is a Lestrade who is even stupider than normal, showing no sign of canon Lestrade's rat-like cunning. Carolyn Wilkinson fails utterly to convince as Irene Norton, nee Adler. The rest of the supporting cast is adequate, with the other standout being Ned Lemley as Stonegrimble, the theatre caretaker, who is seemingly channeling Riffraff from The Rocky Horror Show.