Turns out the Autopage and Clifford LCD key fob alarms are very similar!
I believe I have the Clifford 479X remote, but looks like it could fit a couple others too.

So, the battery cover on my key fob was missing when I bought the truck. Annoying, but eh, not annoying enough to do anything about it... Until yesterday. Yesterday I finally got around to doing something about it and I was a little surprised that it appeared I was the only person with a 3D printer who had lost the battery cover to their Clifford alarm...

Also, it turns out that Clifford no longer sells this remote or any parts for it. And getting a new remote is expensive, and who wants to deal with reprogramming, and, and...

But all was not lost! While browsing I came across the cover pemlasota designed for the Autopage alarms and it looked strikingly similar... So I tried it out - 15 minutes later I had something close, like I could almost force it to fit close! So I scaled it down, tested, scaled it down a little more and BAM! IT fits! The only difference I see it that top outside corner radius doesn't quite match - but I can live with that, no more battery falling out!

Thanks pemlasota for sharing the model!

Here's a quick video of me installing the new 3D printed battery cover and another fob upgrade:

https://youtube.com/shorts/lsFaKXs3awg?feature=share