I had never heard of the Culver Dart before. It has a remarkably low aspect-ratio. I wonder what the thinking behind that was.

To fit in smaller Hangars ?? :)

Probably showing its racing pedigree.

Not too far off - designed to use low powered engines - and it was eventually a Mooney!

from Wikipedia:-

"In the early 1930s Al Mooney was working for the Lambert Aircraft Corporation, builders of the Monocoupe series aircraft. He designed a small two-seat monoplane, the Monosport G.[1] When the company ran into financial difficulties Mooney bought the rights to his design and with K.K. Culver formed the Dart Aircraft Company.[2] The aircraft was renamed the Dart Dart or Dart Model G.[3]

The aircraft was a low-wing monoplane designed to be light with clean lines to enable it to use low powered aero-engines. It had a fixed undercarriage and a tailwheel. The initial version was named the Dart G powered by a 90 hp (67 kW) Lambert R-266 radial engine. That engine was in short supply, so the aircraft was fitted with a Ken-Royce engine and designated the Dart GK. The final version was the Dart GW powered by a Warner Scarab Junior radial engine. Two special aircraft were built with larger engines. In 1939 the company was renamed the Culver Aircraft Company and the aircraft was renamed the Culver Dart."

Here is the next one. Somewhat older than the Culver Dart:-
https://cimg8.ibsrv.net/gimg/pprune....552b78e200.jpg

looks French to me

also one of those rather bizarre engines with bits poking up into the pilots line of sight that seem to have been all the rage mid-way through WW1

This one was not French, Riwever it was built towards the end of WW1.

American??

Not American, it was British.

I'm baffled - I shall go and re-read my Putnam's..............

Something like the Wright 840 Admiralty?

How many of these were built?

Not the Wright 840 Admiralty. Only two were built. The Company that built this aircraft did have a connection with the Admiralty.

Fairey N.10?

Not the Fairey N.10. The reason the aircraft did not go into production was because it's general handling had not got the requisite qualities required for the purpose it was built. As the Machine was not fast enough for other use the original order was cancelled.

I did reply but that seems to have been deleted (?). Beardmore engine?

No the engine in this aircraft was a Rolls-Royce Hawk.

Looks vaguely familiar, but I'm short of inspiration so I'll leave it to someone more sage than I.

Avro 504F? Although my source suggests only one was built.

Not the Avro 504. However, this aircraft was built to meet a contract to produce an aircraft that had a more robust construction than the Avro 504.

I guess there is only one picture of this almost mythical beast?

You may well be right. However, this Company went on to produce a float-plane whose air-frame differed very little from this type.and many components were identical. The engine however was different it was the 150 h.p. Hispano-Suiza..