Thanks, ChuckP... I thought I'd drop a follow-up in case someone finds this thread, looking for the information some day. The tilt angle badge is mounted on three plastic pins, glued into the head. Prying it off revealed the culprit hex bolt that simply needed tightening. I like the older head (pre-1985, I think) without the catch pin on the plate lever and had forgotten that difference until I put the newer head on these legs. Only 30 years of use and already having trouble with this head!