Keep in mind, Damdeok’s collection is like the cream of the crop, with a great many that are difficult to obtain. It’ll all rest on your passion for collecting and the depth of your discretionary income! 
Speaking of language capabilities being up to the mark, did you find that living there gave a significant boost to your language skill? Also, do you have to speak Japanese at work, or is English spoken?
Fascinating to hear you’re involved with design of components related to transportation. As drifand mentioned, there’s this small motorcycle outfit that designs components for motocycle modification. Araki F Machine. And the chief designer made a side project to design a pen, the MechaSEA B1-000. It’s a beautiful thing, not just the pen, but the case it comes in.
Lastly, when you head back home are you returning to India? What city?