There is a gentleman over at Lansing Heritage by the name of Rick (Saeman) who took over for Zilch on the Zilch Cloth Emporium that has original JBL grille cloth Black & Blue I have aquired 2yds of black for my Altec 612C's and it is Identical to the brown cloth that came on my 19's a diamond pattern only differance is the diamond is alittle smaller tighter weave.I think Altec and JBL used the same cloth manufacturer.You may want to try some I think you would be much happier than with Burlap.$15 a yard I can post a pic if you would like a lookie.And use a Weldwood Contact Cement (Original) the smelly stuff for applying it to the grille frame.

Also try Photobucket or Flickr I think Flickr is easier though http://photobucket.com/ or http://www.flickr.com/ and if you use these sites then you just have to post a link something you may want to try.