List of terms people use to mean "thingie" = fun for me, as we mechanical engineers love our specific terms for doohickeys — ratchets, ...
read moreList of terms people use to mean "thingie" = fun for me, as we mechanical engineers love our specific terms for doohickeys — ratchets, pawls, involute spline gear teeth, four-bar mechanisms, you've already nodded off. (We Mechanical Engineers are delights at parties.)

Glad that Bruce mentioned the lack of DOOHICKEY, which I was searching for as I solved. But I was impressed to see such a wide variety of terms — getting seven of them was pretty cool. THINGAMAJIGGY and THINGAMABOB are more highly scientific terms than THINGAMAJIG, but we'll let that one slide. I wasn't sure what a DINGUS was, but it checks out fine as a synonym for "thingie." Just don't look it up on Urban Dictionary. Ahem.
Impressive execution given so many themers. Yes, many of the themers are short, which makes this task easier, but seven themers of any length is a challenge. Bruce did a good job of keeping his fill clean. The places that would typically be the hardest — around MONA LISA and CREDITOR, which pass through three themers — are pretty darn good. IN RED usually sticks out like a sore thumb as a partial, but given the Santa clue, I give it a holiday pass.
Since some themers are very short, just six letters, it would have been nice to lay out the grid so that the longest across answers (including fill) are only six letters. DEADEYE and STUDIOS make for nice bonus material, but they do make it harder to pick out where the theme answers are. (I highlighted them below in blue, to make them easier to see.)
Great clue for LOGOS! I had to read [Shell's shell and Chevron's chevron] a few times before getting that. I forgot that Chevron's logo is a set of "chevrons"!
So, a good grid execution with just a ONE (A) - TWO (EGG) punch of gluey bits. (And TWO EGG is (mostly) fine; I just couldn't resist the joke.)