I'm looking for Yehudah ibn Balaam's Commentary on Yechezkel.
Is it available online (whether scanned, PDF or otherwise)? If so, where?
It's available for free on the Genizah website. All you need to do is sign up (for free), then go to the Judeo-Arabic section and look for his commentary on Yechezkel. The first thing you'll see is the Judeo-Arabic text. Click on the button that says to view the scanned work and you'll see the scans of the printed edition that includes a translation.
Step-by-step picture explanation (for some reason it appears that this section of the site isn't entirely in English):
Clicking on it will open up this search window:
The first search option has two lists. The top one is the list of authors and the bottom one the list of works.
Select Ibn Bilam's name from the list:
And then the bottom list will feature all of his works that are available on the site. Select his commentary on Yechezkel:
This will open this window:
As can be seen, we are seeing the text version of the Judeo-Arabic. On the left corner there are options for what to view. If you select צילום מקור, you'll get only the scans of the printed edition with the Hebrew translation on the bottom:
and if you select צילום מול העתקה, you'll be able to see both the text and the scanned edition side-by-side:
On the right side of the page you can select chapters and verses (missing verses signifies that he didn't comment on them):