not sure if drilling would work given the plastic chassis is extremely thin. This may be my next project. i will keep the existing wheels instead of the bogies due to the complexity of conversion.
My Trackmaster/Tomy/Plarail Photo Gallery Page (over 600+ photos and still under construction)
https://www.flickr.com/photos/183311600@N03/
https://www.flickr.com/photos/183311600@N03/