Ruby treatment

If one should perhaps lay one's hands on a parcel of some vintage rubies (now I'm being mysterious, but the deal isn't yet done)...

I have a well established relationship with a seller clearing a jeweller's estate and they say that the quality is not up to the standard I normally buy from them. However, the rubies are untreated and these days lead-glass sealing of surface blemishes is not considered so outlandish as it once was. So, I'm considering a purchase. Does anyone know how to effect this treatment i.e. any establishments that would undertake this rather than taking a torch to some Waterford vases or the like? It should go without saying that such treatment would be declared where it was undertaken.

Do they have to go back to Asia or are there UK / EU labs supplying treatment?

Thanks in advance.