At the same time as starting this thread I wrote to the company asking for their help. When I've asked questions of other companies they've frequently ignored me, so I thought I'd ask the forum as well.

You're right that some of the cranksets on the site look both delicious and nutritious. I can't comment on your experience with the Sierra crank, but my Premier groupset is still going strong after 20 years of service, the only exceptions being a headset that wore out and worn friction washers on the shift levers.

On the site, the Mistral crank looks to be the top of the line, so I'm wondering if that was true of the 80s Mistral as well.