I've always been wary of mixing oldstyle and lining figures, except in very specific ways. For example, a number associated with a software version might use lining figs while the software itself has initial caps.
We're revising the company business cards with the new logo, and I'd love to see oldstyle figs there. But they look a little busy in multiple lines of phone and fax numbers. But they look great in the address. Would it be crazy to use OsF in the address and not in the phone numbers?