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 (USA):
|New Saito T2dr Model Ship Steam Engine||04/2019||$509.00|
|Saito B3 Boiler And Alcohol Burner And||06/2019||$399.99|
|Saito B3 Brass Boiler Steam Plant Rc||07/2019||$202.49|
|Saito Model Steam Engine Oe 1 Ob 1 Set||06/2019||$150.00|
|New Engine T 1 For Model Ship Toy Marine||06/2019||$149.90|
|See all sold items for more prices|