The Pioneer package was an option over most the the production of J10/J20. Only in 1975 was the wood grain wide like the Wagoneer which was also a 1975 Wagoneer Custom feature.
1974 year J10/J20 Pioneer had this wood arrangement. I am pretty sure it was also used in 76. The Pioneer was not always about wood grain.
This topic has been beat on a few times...