Okay, take two at uploading images.
I know this is old, but I happen to have a FinFun amp and a Guppy, so I thought I'd put them together and post an image. It does technically fit, but it doesn't really fill it out properly, and though I haven't tried swimming in it I feel like the extra fabric might cause a little drag. Here's the amp in the guppy:
Attachment 43872
I really want to upload a photo with the Linden, but no matter what I do I'm told I've "exceeded my quota" and no amount of resizing or deleting my post and trying again will let me upload it, and I'm not comfortable using imgur.