Tony : If that is a picture of the 1968, Deluxe, Simulated Wood Grain Steering Wheel (i'm not that familiar with 68's), then yes, that is what you should have, according to your Marti Report.
Interestingly, the 1968 Sales Brochure that I have, dated 12/67, does not show the Deluxe Steering Wheel as a separate Option. However, the "Mustang Option and Accessories" pages in the 1968 Model Introduction/ Facts book (the fact books were normally available at time of Model Introduction), does show the Deluxe Steering Wheel as a separate, "Regular Production Option" (RPO), as well as being part of the Interior Decor Group (see attached copy of page from same).
Hope this helps.
Bob