Thanks for all the input.

It's not a gag kilt. But there is a gag involved. As a present, it will really work only if presented as a surprise since there will be several expectant contributors here. Basically, he will be given a tartan tie with the message we all pitched in to buy it. Then his kilt will come out as we watch him try to put a smile on it. As will several people he is not expecting. We're Glaswegians, we have that kind of humour.

There will be no gift certificate since, as a holder of trade accounts with all the major mills and with my own access to kiltmakers, I will be supplying it at cost price. I have had kilts made before to good effect. Two for a member of this forum in fact. For this reason, no-one else will be involved in taking measurements but me. I measure approximately 100 - 150 people a week for kilts and I know him very, very well so I have a very good idea of what it will be, I basically need confirmation of what I suspect.

I could present him with the cloth only. It was agreed that would be a nice present but given the crowd that are going to be there and the nature of the event, the gag kind of relies in sending him off to put it on. We would also like great photos of him in the kilt to keep as a memento. If I took measurements for a kilt off him without a very, very good excuse, he would smell a rat and guess pretty quickly that a couple of dozen people are actually, unbeknownst to him, travelling several hundred miles for his birthday party while he is on holiday.

Help so far has been excellent as I expected here. Thanks again everyone.