Hey Eric, the TR77 looks like another B18 platform gun. Do you know if it is ?. The stock might be an interesting swap on a phantom.
Might be cheaper to just buy this gun Paddy! I have taken apart several of this platform guns so at least I could fix it if I needed to. I think the b-18/19 is a good starting point for new airgunners to learn on!
Confucious says: He who slings mud, often loses ground!