Have you tried hashcat yet?
Wish you find your coins, good luck.
I've spent close to 250k since 2014 on this, so, yes.
Bruteforcing is no option.
Dave succesfully recovered a wallet holding +- 1800
BTC around the same time (lost all passwords the same day), so i know he's a capable guy.
If he tells me after almost ten years it's impossible using the bruteforce technique, then i trust him.
I guess i'll wait it out until our technology evolves.