I searched for it for years. Even bugged the Denver networks. They wanted huge money to look into their archives. I'm betting it's there. Lyle was hugely popular in Denver, so a battle between him and another contender like Bonavena HAD to be filmed.
IMHO Bonavena had had it by 74'. Lyle was simply trying to build a resume. Not seen the fight but I'm sure it was nothing more than an aging, plodding Oscar landing a few shots here and there with no significant effect and Ron being the more crisper, cleaner lander. No more, no less. Personally, I have no interest in this fight, it was probably no more than a semi one-sided UD for Lyle. Side bar: Show me ONE quality win for Lyle in his entire career. I'm not trying to trash him, only to show that, given the years he rose to contender status, he really never showed his meddle against a great. Shavers? OK you get that one but if the Huge Left Hook from Earnie had landed mid-2nd round Ron would have been in a puddle out like a light.
Lyle was good. He started boxing late in life but earned a shot at the HW World Title anyway. Lost a decision to a much more experienced Quarry when he was on his way up. IMHO Lyle became a better fighter than Quarry. Lyle gave Ali and Foreman problems (dropped Foreman twice) before getting stopped by them... Quarry was clearly beat in most of his biggest fight (KO by Ali x2, KO by Frazier x2, and KO by Norton).
As i recall Ron's 3 round KO of Larry Middleton made a lot of people sit up and take notice, Larry had Floored, Broken the jaw, and beaten Joe Bugner, stopped the capable Bob Stallings, and lost a Razor thin decision to Jerry Quarry, so at the Time Larry was a capable contender. After he settled into trial horse mode, he still had enough to draw with Ellis, and lose on points to Messers (Lyle Again) Bonavena Bobick and Ledoux, towards the end it took Kenny Norton 10 rounds to stop Larry, and he did not look good doing it. Lyle's 3 round KO over a very Ambitious Contender Larry Middleton was a notable result i feel. as indeed i and many did at the time.
He had a lot of quality wins against tough fighters. Were they great fighters? Probably not but they were still wins over big names/tough fighters. He beat Buster Mathis, Jimmy Ellis, the aforementioned Bonavena, Earnie Shavers, Stan Ward, Joe Bugner and a slew of other tough journeyman types. As he was slow and ponderous, he could be outboxed (Quarry and Young) but he gave 2 all-time greats in Ali and Foreman tough fights. He is still the only man to deck the pre-comeback Foreman twice and gave him a much tougher fight than did Frazier or Norton.
Lyle would have been a tough out in any era. But?...outboxed by Quarry? When did that ever happen? Foreman was ''brain-fried'' after Zaire but no way Lyle doesn't wind up in a puddle against George which he did. All the other fighters you mentioned were either ''journeyman'' or over the hill. Post-Foreman Ali results IMHO will never impress me. I consider Ali the greatest HW ever but, in retrospect, his post-Foreman career was a "dodge-em" snake oil ''circus". There were several really good fighters in the 70s without quality wins, Lyle, Bugner, etc... that were really good. But facts are facts. And I'll take Jimmy Young's "Lyle-Lyle-Ali-Foreman-Norton's" resume over both of them.
Quarry outboxed Lyle in Feb. 1973, UD 12. The cards read in favor of Jerry; 10-2, 9-1-2, and 7-4-1. As the bout went on Quarry's counter punches landed often and sharp causing the bigger punching Lyle to cover up more and more over the last third of the 12 rounds. One of Jerry's premier wins.