Scotty, I can't help directly with your question, but a thought has struck me.

Why not go back to your hire company and find out who their original supplier was. Then contact them directly. From what I understand, the kilt hire industry in the UK replace their garments in October/November. New stock coming in for St Andrews Day, Hogmanay and Burns Night. So either your kilts were sold off last year or will be sold in a couple of months time.

Might be worth investigating.

Regards

Chas