Proper recipe for Singapore Sling?

I was curious to try something different and had never made one.

I'm using 2 measures of Gin, 1 measure Cherry Brandy, 1 measure lemon juice, 1 tsp Grenadine, a lime peel and a splash of seltzer. The blurb for this recipe says it's a thirst-quencher, therefore it's not very sweet and that's how mine turned out.

But, I'm reading on the internet other recipes that suggest it's a sweet drink that uses Cherry liqueur instead of cherry brandy, pineapple juice instead of lemon, Dom Benedictine and Cointreau.

Which is correct? Both claim to be the recipe created at the Raffles Hotel in Singapore in 1915.

Lastly, is there a significant difference in the level of sweetness of a brandy distilled from cherries called Kirschwasser flavored Brandy versus a Leroux artificially flavored cherry brandy?