I'd been wanting to build up a lightweight gravel bike with similar frame. For many years I've kept eyes out for a larger 60cm Cannondale ST framesets, maybe one of their ATBs? Cannondale, Klein, GT, Giant and others were making alloy framesets in the 90s but I've had a tough tie finding anything worthwhile all these years. I'm sure there were probably others out there I'm missing.

Will be interested in following this thread, see where it lands.