Cocktail history is drunk history and the folks who recorded it were probably as drunk as you are about to be after drinking this. That makes older a drink is the harder it is to nail down. Any site you visit or vintage book you find will have a unique recipe for this punch. So take mine as just another variation and feel free to make your own too. This recipe taste to me like a grassy margarita. My wife was pretty skeptical of it when I poured her a glass but after tasting it was impressed. She loved it and the first words out of her mouth were ‘oh that’s good! Taste kinda like a margarita but more green tea like.’
Every recipe contains a mixture of (grape) brandy, peach brandy, rum (dark or gold), lemon juice, sugar, and nutmeg. Where they differ is some sources say to lengthen the drink with water and other say to use black tea. The black tea taste better and adds a nice grape skin like earthy tannin taste to it, where the water just makes it taste like a normal sour cocktail. It also makes more sense to me based on the time period it was most likely created, mid 1700s to early 1800s, that they would use tea. Tea was popular, and like beer it was safer to drink because to make it you need to boil the water which kills most of the germs. The people back then didn’t know about germs yet but from observation they knew that beer and tea made people sick way less often than normal water.
The last thing to play with here is the proportions of all the ingredients. I provided what I feel is a good balance but modify it as you like. There is no canon recipe so your variation is as good as mine or anyone else’s.