Buck with the "West Coast", Steve Miller-akin pop voice (as on Reaper, Shooting Shark, Then Came The Last Days Of May or Burning For You) plays the Steinberger and has been doing so for ages, Eric (the monk-hooded singer in the vid) with the gravelly melodramatic voice (Godzilla, Cities on Flame, Dr. Music, Veteran Of A Thousand Psychic Wars, Harvester of Eyes or Astronomy) plays the "Symbol Guitar" (referred to as "Stun Guitar" on old BÖC albums), he rarely, if ever plays lead, but doubles on keyboards. The guy with the EBMM guitar is a "new" guy (though with the band for more than a decade): Richie Castellano. He is someone's relative here on the forum. Initially, the replacement for former Patti Smith squeeze Allen Lanier, he played more keyboards at the beginning of his tenure, but has by now become their third creative force (sort of like the Bouchard brothers were before they left), playing lead guitar and doing lead vocals on some songs. He wrote about a third (or more) of the new album and has really stepped up to the plate.
It's telling that you got confused about who is who - that was always the millstone round BÖC's neck: With all five of the original line up singing lead (as a result, BÖC's harmony vocals are idiosyncratic and hugely underrated), all of them playing guitar (the legendary BÖC guitar row during Buck's Boogie where even the drummer would strap a guitar and leave his drum stool), the original drummer (Albert Bouchard) also playing keyboards and guitar, one of the guitarists playing keyboards (Eric Bloom) and the keyboarder (Allen Lanier) playing guitar, nobody knew who was doing what at any given time! Eric Bloom once said that their individual versatility hindered their success, there was no frontman to latch onto for the audience. While Eric was no doubt their focal point during live shows (with Buck Dharma taking more spotlight over time as his songwriting and lead vocal share increased once the Bouchard brothers had left), he didn't sing the real big hits, Donald "Buck Dharma" Roeser did (Eric's voice was a bit menacing and foreboding for ultimate commercial appeal - I continue to hold that it was an inspiration to James Hetfield's vocals).
That these guys - along with Grand Funk Railroad and J. Geils Band - aren't in the RHOF is a cryng shame. They epitomize "Yank thinking man's hard rock" to me, how many other US hard rock outfits can you think of that had lyrics penned by Patti Smith?