Hello,
That is an interesting request. As far as I know, there are no longer any makers of this French silk millinery veiling. After WWII, the French stopped making it, and veiling was made of rayon followed by synthetics such as nylon which you find today. That is why the antique silk veiling is so precious today. I collect this stuff and any I have in my collection were all made in France. I do not know if there were any textile companies who made silk (or rayon) veiling in the UK. If there were any, they are no longer in business. I am based in the USA.
Any makers of veiling today use synthetics such as nylon, and as far as I know no one is making silk veiling today. The sophisticated antique machines used to make it no longer exist, and the pattern cards for the looms are probably not available. All the veiling made today is fairly narrow in width as well. The old stuff was made in much wider widths, up to 20" or more and there were dozens of patterns. All you can find today is synthetics veiling in 1 or maybe 2 simple patterns, in narrow width of 9 to 11", and made of nylon. Just not very good stuff in comparison.
Even if you did find a textile mill who had the antique looms and was willing replicate your veiling, they would want to make it a specialty order and you would have to pay for a huge quantity such as 5000 yards minimum. They are not going to make a small amount for you.
My suggestion is to browse on Ebay until you find a replacement veil. I often see them. If you are trying to match an exact pattern and it is a fancy pattern, of course that can take longer.
Sounds like you have a good hunt on your hands, and best of luck!
) - can anybody recommend anyone in the UK ideally that could do that?