I would respectively disagree with a number of your choices, with Somewhere I'll Find You being a particularly weak film. I think a much stronger and interesting set would be:
Across the Wide Missouri
The Hucksters
Red Dust
Test Pilot
They Met in Bombay
Too Hot to Handle
If Test Pilot gets included in a Spencer Tracy box set and/or Red Dust gets inlcuded in a Jean Harlow box set then I would suggest as replacements, the early gangster film "The Secret Six", although Gable only co-stars with Wallace Beery in the lead, and "Honky Tonk" which you had mentioned.
c Jim Bur