Can guild specific items be bonded or altered with LTBs?

i.e. thieves guild weapons

More than one alter-er at the last Hollow Eve told me that you would need a specific thief merchant (are any even alive?) to do something like Fade or Ambika weapons.

That said it continues to drive me insane (in the membrane) that LTBs are so limited.

At 1 per account per 9 months, and only if you pay an extra 25 bucks for each of those 9 months, they are, to me anyway, the rarest and most expensive form of alteration in the game.