I grabbed an E120 and tried this also. Didn't really work out very well for me. Put it in a cab. It got a little closer to the tone but I didnt really like it. I don't think 15 watts does that speaker justice. I had the same idea but after the speaker and the mods I would have had a $1000 BJ. Scrapped the idea, sold the BJ and bought a deluxe reverb. Much happier.
"Mama said, don't go near that river."