After long searching on the internet for the solution, I found this topic and finally my answer - a working tool to be used offline, at https://github.com/saleemrashid/nem-trezor-standalone Thank you gentlemand (!!!) for opening of this thread, for discussion here. Getting a tool allows us to have full control over our private keys for NEM, even when Trezor is broken or lost, not replaceable by another device. Our keys = our coins. Everything we need to know then, with the generator, is our seed and our password. It even allows us to download the wallet exported. There are generators for other coins out there but they are mostly using secp256k1 curve, instead of Ed25519 curve, used by NEM. Kudos to both  of you gentlemand and saleemrashid !!!