All parchment interior/trim in a 1967 Shelby GT350 and GT500 are coded as '5U'
'5U' is a knitted / comfortweave trim.
There were no '6U' parchment trim (smooth) used for any 1967 Shelby built by Ford, completed by Shelby.
~257 total parchment units were built at SJ for Shelby American (SAI).
There is more detailed info in the link for those interested.
https://groups.google.com/g/shelbyresearch/c/xMh2RMLAXdc/m/QK_NnjGNBQAJThe SVO sheet sets (for a DSO group) are identical in package, except for paint colors, with very few exceptions
(The exceptions are DSO 84-2534, -2536, -2538, -2540; first emission equipped engines delivered late to the production line in SJ.)
The photo posted above is for DSO 84-2562 with 15 units...all with '5U' trim.