I noticed someone awhile back was looking for the custom 300 tailights (with the reverse lights in the taillights. I see a pair on ebay right now.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=34204&item=2421497259

Hope this helps someone

My 68 300D came with those taillights you're talking about. So I personly think that they're not custom.

Zac