If you're looking for (new) parts, they have them but their website is mainly in Japanese. Here is their parts page in Japanese and here their site in English. On their 'Distribution' page you'll find contacts.
What's your 'Saito Steam' worth? Here are some recently sold items (UK):
|Saito T2dr Twin Cylinder Steam Engine||06/2019||£ 250.00|
|Saito T2 Model Twin Cylinder Steam||05/2019||£ 200.00|