lamps trimmed and burning

i'm really digging this version of keep your lamps trimmed and burning and its inspired me to learn clawhammer. 

http://youtu.be/i6PnyrRnxLk

I've got some of the melody down but im running up against a few setbacks.  Can someone help me with the chords first?  I think its  Em ---- Am ---- Em ---- A7 - B7 - Em.... then Em --- D?? --- Em --- A7 - B7 - Em

any help would be much appreciateD!