Doug,
I have a Meade LXD55/75 counterweight (10lb or about 4.5kG) spare. It is the white one from a LXD75. Probably not heavy enough for u though
http://www.optcorp.com/product.aspx?...5-183-185-6900
I can double check its weight and inner diameter. The Meades have a known issue with the locking screw lever easily breaking off (it's happened on 2 of my three cws)
Cheers,
Darrin...