The lugs, fork crown and the Davis Components bottom bracket shell, as well as the wraparound stay treatment were employed by multiple marques, but that serial number makes it almost certainly a Witcomb (of London). The number would indicate 1973 manufacture, most likely the second half of the year. Serials from 1010673 to 1017073 were for frames built the last week of July 1973 (see this post and the video there).

Witcomb were custom frame makers (with some then and now famous builders working for them), so feature-wise you could have many different combinations and styles.

Here are some examples of serial numbers, etc: