Welcome to the forum. I'm not sure how much you already know, but MTB 730 was a Fairmile D 'Dog' Boat. She was built at Woodnutt & Co in Bembridge on the Isle of Wight and was completed on the 28th April 1944. At Normandy, she was the lead vessel of the 63rd MTB Flotilla, under Acting Temporary Lieutenant Commander G. C. Fanner, DSC, RNVR. There's a picture of sister vessel MTB 724 here: http://www.iwm.org.uk/collections/item/object/205124877
. She was part of the same Admiralty order but was built at a different yard, so the exact configuration may have differed a bit.
There's a diagram of 730 in the book Dog Boats at War
, by Leonard Reynolds (Sutton Publishing, 1998), dated to December 1944. She looks almost identical, except that the fore and aft guns are 6 pounders mounted on MkVII mountings. This may have been the result of a refit, so it's possible that her configuration at launch was the same as 724's photo. There's also some more detailed drawings of 730 in Coastal Craft History Volume 3: The Fairmile D
, by Mark Smith. These are based on original line drawings by John Lambert, but the colours in the book appear to be based on Admiralty instructions, so I don't know if Mark found any pictures to assist him. He is a member of this forum, so you may be able to contact him.
The drawing would appear to be the only entry for 730 in Reynolds' book, but there's a bit about the 63rd Flotilla. She clearly saw a bit of action around D-Day. As it happens, Coastal Forces at Normandy is something I'm researching at the moment, so I'll let you know what I find relating to 730 in the Admiralty reports at Kew.