Hand Tools
1x Clock Wall Stabilisers Clockmakers Fixing Repair Service Parts Tool Vienna
Listing is for 1x only if you need a pair buy 2 of these. These made for fitting clocks to wall, prevents clock moving. Base is 40mm long and 14mm wide at widest. Screw head is brass.
https://www.bizrate.co.uk/handtools/1x-clock-wall-stabilisers-clockmakers-oid19111582878.html