I just found my copy of the entry list to Indy in 1969. Wally Booth is listed in the SS/E 1969 Dodge. Dick Oldfield isn't in the list at, but the Iron Butterfly is under the name "Jeg Spehar" with the same competition number Dick ran on the car at Dallas later on that year, #1341.
I don't mean to confuse things, but I'm still pretty sure Dick was in the Butterfly at Indy that year.