Vintage T-Shirt Forum & Community Authentication Appraisals

Good evening
Has anyone got some info about tees that have a label with the number 1 inside a circle followed be the word ‘Vintage’ ?
Searching is a nightmare as the word vintage always leads to the sale of vintage clothing ,which is how I found this site!
Any ideas please,as I’d like to get hold of some as the necks on them are nice and tight.
Please see pic.
Cheers

Not familiar with it... most items with the word vintage are not...

I don't think that's a "1". I think it's a golf flag in a hole. Maybe that will help in searching?