Unfortunately I know as a backyarder I would not take one for the very reason Shadrach outlined. Chances of contaminating my own flock so so high :( Not much future for those show birds.
Another option is to perform your own necropsy if you loose another expected case to Mareks. If you do that and post photos in the emergency forum there are people here with a great eye for autopsies and a lot of experience who will tell you what they see. Also, if a bird passes from Mareks...
@Morgank it's terrible you are unable to get a necropsy performed to confirm whether or not Marek's!
Some people on here do breed within their own flocks (from non-symptomatic birds in their flock) when they have confirmed Mareks. The reason being the chicks that survive have a resistance!! So...
I gotta say, when I came across this forum I breath a Huge sigh of relief, I was Convinced my chickens were going to freeze to death during the winter, especially if it got below minus 2/3 (celcius) :D
I've got to admit, when I saw the tag for this thread I thought it to be a mistake. It's a rarity (in my experience) that Ireland is considered part of anything :D We're too small!