Will this fit

[MusicManJP6]

Yes.

 

[MrMarkIII]

FWIW, This one looks in better shape, and looks like the EV's Mesa used. The ones with "fins" and the "EV" logo on the dust cap are later, not original equipment in Boogies.
http://cgi.ebay.com/Old-Electro-Voice-EVM-12L-8-Ohm-Guitar-Amp-Speaker-EV_W0QQcmdZViewItemQQcategoryZ121165QQihZ015QQitemZ250381489417QQrdZ1QQsspagenameZWDVWQQsalenotsupported