I have an older BORG 100ED objective and collar for the 80mm tubeset. This cell, from maybe 1994, is not collimatable like newer ones. I bought it used as part of a complete 100ED 80mm OTA from a reseller in Japan, but have since acquired a 125ED, and cannibalized the 100ED parts for a 76ED. QED. (snicker) It produces fine images, nearly colorless, typical for the BORG ED objectives. The rear element is a little dirty and might be cleaned, but I have not touched it. You can buy Part #6000 (80mm Dia. Tube set) plus a lens hood to make a complete visual OTA, or it can be used with a 114mm dia. tubeset for medium format photography at f/6.4 or f/4.
$300.00 or best offer. Paypal accepted.