Marui shogun 4wd

[Mattw2053]

Hi all
I've just come across my old rc cars whilst clearing my parents loft one is a marui shogun the other is a tamiya lunch box. Both still work and run however the tyres are ruined ( I guess sitting unused for 15-20 years causes this) the lunch box is not an issues as parts are easily available but I can't seem to find any parts for the marui shogun ideally I only need 4 tyres to fit but I have no idea on sizes etc if I can't find the right size tyres then I need 4 wheel and tyres to suit. Anyone got any ideas where I can get replacement tyres or what wheel and tyre combos will fit and where I can buy them.
Thanks
Matt