AMONG THE various eccentricities that have remained with me for long, the one my friends consider the most peculiar is collecting postage stamps. I can’t claim to be an expert philatelist, and my interest in my multiple stamp albums is often sporadic. Yet, whenever I happen to be in London on a Saturday, I try to make my way to the Embankment Tube station and walk a short distance to a basement where stamp collectors, coin collectors and accumulators of military memorabilia gather to buy and sell. The Saturday fair is where I pick up bargains and the missing stamps of my George VI collection.