Check this out. Datamancer's Sojourner keyboard might be a candidate for an unusual keyboard, especially if the recipient is well known to have great love for all steampunk products.
The keyboard itself comes crafted in polished brass and is artificially tarnished to make it look much older than it is. All keys look slightly weathered keys and are electroplated in brass to complement the aged leather faceplate and parchment key inserts.
Check the thumbs and be amazed ...