I have met this type of response before from a a few Valve Sellers.
Some individuals try to bully the sale through, and resent a reasonable inquiry being made.
My own line of inquiry can really inflame these types of individuals unsavoury side.
Buying Valves is a Caveat Emptor undertaking and the devil is in the details.
I Buy Matched Pairs usually, but don't buy Valves now, unless the Vendor agrees to the request being made by myself to have the Valves measured on a Third Parties Test Equipment.
If the measurements are a close match to the advertised ones, the sale is completed as the Valves will be retained by myself.
If the measurements are quite different, then the Valves are returned and a refund is to be given.
As said I have encountered varying types of personalities, most importantly, I have had great success from very helpful vendors.
The less helpful and those that are quite Obnoxious can retain their Wares in thier keep.