mention of house numbers being "new":
In matters of this sort minute exactness as to situation can be of little importance, but the modern custom of numbering the houses will enable me to point out the places of most of the ruins with tolerable accuracy (Combe and from Jackson 1787: 116).

difficulties of not having numbers (or maps, or drawings) & having to write everything out in (often) excruciating detail:
The house, in the garden of which the Roman pavement with the wheat under it was discovered, is situated nearly opposite to St. Martin's church, in Angel Lane, which turns out of the great street on the left hand just below the Moot-hall, the present play-house. The house is on the left hand of the lane, and the church on the right, going from the great street. Two years ago another pavement, still more rudely formed, with something of an arch under it, was discovered in the further end of the same garden; and some years before that, other pavements of the like kind were found, both under he house next above, inhabited by Dr. Daniel, and also under or near the house next below, inhabited by Mr. Wall, in the same lane (Griffith 1773: 290).



Combe, C. and Jackson, J.
1787 Account of the discoveries in digging a Sewer in Lombard-street and Birchin-lane, 1786. In a Letter to Mr. Gough, and communicated by him. Archaeologia 8:116-119.
Griffith, G.
1773 Account of a Roman Pavement, with Wheat underneath it, found at Colchester. By the Rev. Dr. Griffith; communicated by Edward King, Esq; in a Letter to the Secretary. Archaeologia 2:286-290.