Marushin M1 Carbine

[Isis]

can anyone help me with this gun? i need a new hop rubber for it, and have had my husband looking for a spare rubber for a couple of years, but he hasnt got anywhere, can anyone direct me to where i might buy a new rubber or suggest a rubber from a different gun that would be suitable?

i have a thread in the wanted section, but if i can buy a new one from somewhere that would be ace!

many thanks!