Welcome Ganjawulung (i love this form of gonjo as well
).
The 3 volumes of Tammens' De Kris are still available AFAIK. I know that at least one dealer who posts here has them available and perhaps he will PM you with ordering info.
I don't believe The World of the Javanese Keris is still in print, but copies do still come up for sale. I think there might be one on eBay right at this moment in fact.