In the early 1960s a pair of very quick Lotus Mk.11s ran in Pacific Northwest events.  Your webmaster saw these cars race twice: once at the June 17, 1962 Portland, OR, "Rose Cup" pro race and again at the July 28-29 "SeaFair" races at Pacific Raceway, near Seattle, WA, on July 29, 1962.

Your webmaster is reaching way back with this, especially with the spelling of Lewark's name and with the ID of his partner in the other near-identical Lotus as Paul Scott.