The press fit bearings themselves are easily replaced. Loosescrews.com sells them for about $5 each (item #UB-6003). The spindles are a bit more of a challenge. I replaced one awhile back with an ActionTech titatinium spindle that I got on eBay for $20. Phil Wood spindles also work but are very pricey. The key is one that doesn't have bearing surface ridges, but is instead smooth. I have seen Viscount/Lambert cranksets selling on eBay fairly regularly (bought one myself a year or so ago for about $20). Good luck!

Neal