My friend Eugene pointed me to a Tektronix 661 on eBay (it was the first one I'd seen in quite a while). I've wanted this scope for a long time. I even mentioned back in Scope Sunday 2.
Jim mentioned his Tek 661 quite a few times: He used it in App Note 74, and tt is pictured on the back cover. He used it in Figure 77 of App Note 72 and also in App Note 61. I'm excited to have my own, and if it works, I'll have to get to work on building some more high-speed pulse generators.