Got these surplus to requirements if they are any use. They are galvanised steel and all priced at £7.50 each delivered and can combine postage obviously if you want more items dependent on weight as they are quite heavy.
Hooks are approx. 320mm top to bottom and suit approx 40mm dia rail
Small gambrels approx. 12mm dia x 310mm long
Large gambrels approx. 16mm dia x 400mm long