Deerhead M700 thumbshifters.....not mine.....but might be just what you need if your trying to build a groupset.
Vintage Shimano SL-M700 Deerhead Thumb Shifters, Friction Shift, 1 Pair | eBay
Very good condition.
www.ebay.co.uk
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.