Old injuries to legs, so very little climbing ability anymore, these days.
Sadly: 275 VAM, according to the suggested calculation. Which doesn't surprise me.
Roughly, back in the day I recall doing a ~300ft climb typically in 10mins or less ... or, 548 VAM. And longer climbs faster still, when pushing. Not great, even then, but these climbs were still post-injury.
Oh, to be young again, but with today's knowledge eh?