Air Arms Brass trigger guard for Pro Sport in the US?

No idea. I have one along with a brass end for the cocking rod on my TX200 from Rowan. Very fine workmanship and finish.
I was at an airgun show/yardsale/competition in Hemit, CA just a few weeks ago and purchased two beautifully crafted brass trigger guards, one for my TX200, and another for my HW97K. Their cost was a mere $20 apiece. I don't know where you are located, but I can't believe that there aren't any reasonable craftsmen in many places here in the States. I've been intending to contact Chambers, in England, in the hopes of finding nicely crafted cocking arms for my TX200 & HW97K. I do like my bling. Orv.
 
I was at an airgun show/yardsale/competition in Hemit, CA just a few weeks ago and purchased two beautifully crafted brass trigger guards, one for my TX200, and another for my HW97K. Their cost was a mere $20 apiece. I don't know where you are located, but I can't believe that there aren't any reasonable craftsmen in many places here in the States. I've been intending to contact Chambers, in England, in the hopes of finding nicely crafted cocking arms for my TX200 & HW97K. I do like my bling. Orv.
I am in small town east Texas. I honestly do not know of any airgunners in the area. I did know of one via another forum but like myself he was getting older and passed away last year.