The amount of AT sections in a Musti platoon is a tricky one, simply because three of the four AT Patrols are not independent units. Eeach Musti squad has an organic AT Patrol of 3 men (the standard AT Patrol) that is lead by the squad second in command (almost always an NCO). In addition to that there's a somewhat rare squad type called Anti Tank Squad. I'm not sure if they are present anywhere else than the Musti Companies. It consists of two AT Patrols, each lead by an NCO and most of the time used independently from each other.
So all in all, that gives us 2 AT Patrols from the two Musti squads and 2 more AT Patrols from the AT Squad. So in total the platoon has two Musti's and four AT Patrols. That's some serious tank stopping power. Well, at least if the tanks are in range, which of course shouldn't be a problem in Finland.
And yes, I'm pretty keen on this particular weapon. It shouldn't be too hard to guess how I spent my time in the army.
