Just a little note about Encumbrance & Coins. In all honesty I don't think I've ever worried about encumbrance, I started with 2nd edition, and it just seemed so mind boggling along with all the other rules. (We were pretty young players). Reading thru the basic rules from 81, it is a bit more straight forward. The rule that I've implemented is from Advanced Fighting Fantasy 2e. Which is basically you can carry 10 to 20 things. I've stuck with 20. Not including coins. It's just a bit easier.
Now onto coins. While I get the point of copper, electrum pieces, I really don't have much use for them . Obviously encumbrance played a factor back in the day, regarding carrying coins. That being said I'm a fan of 10 SP's = 1 GP's. And that's it.
Do you worry about all the extra coin types?