John, try these. On sale on eBay at the moment.

270659032210 - 50 of 10mm Flat Pad Tie Pin & Clutch - £10.50 - Buy it Now

or

270659032207 - 5 of Silver Plate 5mm Flat Pad Tie Pin & Clutch - £1.50 - Buy it Now

I did a general search for 'clutch pin' and when all 5 million items came up, refined search to 'craft'.

Hope it helps

Regards

Chas