The main problem with the Checkpoint is it is not rated to carry as high a load as the 520. Gearing you can for the most part get close.

There is the Trek 1120 and their Dual Sport.

There are some 520s at shops. A few months ago it was possible to use the Trek web site to find them. I don’t know how to do it now. But I remember a Trek dealer on Charlottesville Va had a couple. It would be tedious but you’d have to search for dealers and see if they list them.

Edit Maybe one in CA


Best bet is n+1. Get a Trek you could use like a mountain bike. Or find a friend that wants a Trek and buy for them. The shop for a heavyweight touring bike.