Making money have weight would be kinda crazy since alot of people like to carry alot with them. and i just don't like the different types of money idea.
Promissory notes are bank notes that you exchange your coins for at a bank.
I did explain this. You can carry any amount you want and have it weigh 0.1
If all coins weigh 0.1 as in Daggerfall you would need multiple coinage, otherwise, as was in Daggerfall, loot money is heavy.
Not so if a silver coin = 100 copper and is 0.1, if a gold coin is 100 silver and weighs 0.1.
Also, in all games since Daggerfall prices have been ridiculous.
A daedric weapon is far too cheap compared to a measely bread.
Again, this is solved by denominations. A bread can be 5 copper, a daedric tanto 500 gold, thats far more realistic.