Hasegawa makes/made a Shinkai 6500 in 1:72 scale. Not sure of its availability. You may need to check with a distributor in Japan like HLJ (HLJ.com)
Back in the day, Viking Models in the US made an Alvin. Walk (no run) away from it. There is a reason that Viking went out of business (actually more than one, but this is one of them)