Chris, you beat me to it.  I also have a build along in the works.  I'm gathering pictures. I went for a linen backed ERC.  I was debating on what to do about the back also.  But I went with my gut( and easy of construction)I will be posting mine in some time next week in the Build along section)   
I've only built 3 ERC bows. All are from trunks. Two were unbacked but only ended up around 38-40# (i was new to bow making). I built an raw hide backed ELB at 50# and took it out one cold day and BOOM! ( but after looking at pictures of FD I could see that my tiller was off, so that was my fault 

) 
 I know you can do it.  And I will be watching, cause I have plenty of the stuff.