From reviewing prior postings on this subject, there is lots of info on part numbers, but I didn't see any on the numbers actually stamped on the fenders. Typically these numbers are the same, that the part number is the number stamped on the part, but not necessarily. Inner fenders of these years are one of the exceptions. I went through a dozen sets of inner fenders that I've collected since the 1980's, and here's what I found. 1969 - no part number stamping on either fender 1970 - 1231153 stamped on left; couldn't see anything on the right (battery damage). Buick part number 1231154(R); 1231155 (L). 1971 - 1237221 stamped on left; again, battery damage obscured any stamping. Buick part number 1237218(R) 1237219(L) 1972 - 1239863 stamped on left; again, obscured. Some have the week-of-the-year stamped below the number stamping, e.g. "35 /" and some have a Julian date, e.g. "240"
Thanks for the info. I'm probably going change my 69 inners so nice to know a 70 drivers side could work as well. Do the passenger side 69-70 look similar as well?
The 1969 and 1970 Skylark inner fenders are NOT identical, and do not interchange. Sorry for any confusion that my earlier comment caused, as I was wrong. I've deleted this note from my original post. One area where they are different is where the inner fender bolts to the fender near the wheel well trim. The '70 fender's wheel cut out is longer as it more gradually drops down as it makes its way towards the rear of the fender. The '69 fender drops rather sharply by comparison.
The Buick parts book shows the same part numbers for '68-69 inner fenders, both left and right, so at least they interchange! 1968-69 3000-4000 Left: 1230449 Right: 1232912
Thank you! I guess I can now put up a “parts wanted” ad if none of my local Buick buddies have any laying around.