1856 Royal Navy Midshipman Dirk from Ellyett, Portsea

[Blackrose]

I have recently purchased a Midshipman's dirk from maker Ellyett which I'm carefully restoring (cleaning and polishing). It's in very good condition, except for the tip of the blade that is slightly broken and some rust patches that appear inactive. The only source of information I have on RN dirks is the book "British Naval Swords and Swordsmanship" by John McGrath and Mark Barton, which confirms its date. However, I found no information on the maker. I'd be grateful if someone wishes to share information about the maker and reference material about RN dirks in general. 

Total length (blade + hilt): 16.5in (41.9cm)

Cypher: Queen Victoria

As this is my first post in this very interesting community, I'd like to thank the team behind it for such a great initiative.

[Blackrose]

I've been trying to find information about how this item was usually carried. What kind of frog is the one suitable for this kind of scabbard?