'Part Number: X1707, X1708, X515 & X516. Also known as X1123/4. If you look at Hornby Service sheets 131 and 131a you can see these part with a screw and with pins in the ends of the coupling rods.
HORNBY A1 A3 A4 LOCOMOTIVE DETAIL ACCESSORY PACK SPARE PARTS OO GAUGE 1:76 SCALE
HORNBY A1, A3 + A4 VACUUM PIPE + BRAKE RODS DETAILING PACK for TENDER DRIVE ONLY
