Complex sentence: Since 2003 they have issued a few full lengths, a split with Mudhoney, an etched 10, and--most famously--recorded the last ever Peel Session with the late John Peel.
Split into simpler sentences: Since 2003 they have issued several full length albums, a split release with Mudhoney and an etched 10. Mugstar recorded the last-ever Peel Session with the late John Peel.