Below is long story of stupidity with a nice tl;dr at the bottom.
Got a hold of a Kindle PW2 from my aunt, it had only been connected to the internet during initial setup and was running FW 5.4.2.1.
When I got a hold of it I didn't initially connect it to the internet and I successfully jailbroke it and managed to get the collection manager on it (which is all I really wanted to jailbreak for).
Then I stupidly connected it to the internet. I wasn't aware that the Kindle would auto-update or that there was a way of preventing it.
So now I have a Kindle running 5.6.1.0.6 which I believe was still jailbroken.
I then (probably stupidly) went into the settings and chose the reset device option.
Fast forward a few weeks and I read
this post by madagascaradam about a similar situation to mine in which he was able to downgrade to a version of the FW on which the collection manager works fine.
I've tried following the steps but haven't had any success in downgrading it though.
I can still access KUAL and I've got the mkk folder with five files in it.
So rather than derail the collection manager thread with potentially solving my problem I thought I'd make a new thread.
tl;dr
How to tell whether or not my device is still jailbroken so I might be able to potentially downgrade.