In reply to Fredt:
Chances are the whole lot will be worth very little, for the following reasons:
1. We used to write a LOT of letters - most stamps were printed by the million, sometimes by the billion.
2. A lot of people used to collect stamps, so old stamps survive in large numbers.
3. These days, stamp collecting is a lot less popular (and socially credible, to say the least!) than it used to be, so demand for material is generally low = low prices.
