Hi Jim
I have to agree with you. The new sound of the Lost Bayou Ramblers is fantastic!
I'm no expert on electric sound but in these clips- link1 link2 link3- in JAMMININTHEVAN in New Orleans is quite clear that Andre is using pedals (about 3 or four) and changes the sound of the accordion quite a bit during the song . It's hard to know what pedals exactly he's using but clearly he's using an overdrive pedal. Louis is using overdrive too!
I haven't answered your question 100% but I'm happy to hear people commenting on the new sound of the LBR.
I hope someone with a better knowledge we'll be more precise. I'm intrigue too!
cheers

Hi Jim
Looking at the videos again and asking for advice about effects to some people i know, this is the guess:
-the two little pedals (blue and brown) look like the TC Electronic pedals: a delay and an overdrive. http://www.tcelectronic.com/guitar/pedals/
-A Jim Dunlop Wah wah (the big one)
-the white pedal is the Boss tuner pedal that I guess he uses for the lap steel. Unless he plays a tunable accordion!!

This is a guess from looking and listening. I could be wrong! I'm human after all.

cheerio