A known thematic trick done pretty well here. Starts of strong with an interesting clue for INTO (1A: Digging ... or word after "digging"). Never heard of ARNEL (16A: Synthetic fiber), but I guess I learned it today.
Frannie was instrumental with some nice long ones like PATTYDUKE (9D: Helen Keller's portrayer in "The Miracle Worker") and the very nice TOUSLES (40D: Messes up, as the hair), but she guessed the wrong persona (Jekyll) for 49D: Half of Stevenson's "strange case" (MRHYDE). Me, I didn't even know to what it referred...
Enjoyed SOUSED (53A: Lit), FSTOPS (22A: Camera adjustments), and the somewhat complimentary ETUDES (47D: 27 Chopin works) and SONNET (43A: One of 154 for Shakespeare). And a nice nod to Spock with 63A: Vulcan mind ____ (MELD).
Oh, and one more thing - ABSSYSTEM (33D: Auto safety system feature, redundantly) I found oddly amusing.
Overall, a decent Tuesday.