Mohan's answer looks possible, *assuming* that "coulage" = "casting."

But there is an ambiguity in the construction "small casting shop": is the shop small or are the castings small?

And there may be a problem with the use of "casting."

It is not clear to me that "casting" is appropriate here --that word is usually used in English when referring to metalwork (molten metal is poured into moulds); though we do have "plaster casts" (usually of artworks).

"Coulage" can certainly refer to a process using moulds:

COULAGE, subst. masc.
A. [En parlant d'un liquide, d'une matière en fusion, d'un mélange pâteux]
1. Action de couler. Le coulage d'une bougie....

...Façonnage ou moulage par coulage (A. BRONGNIART, Traité arts céram., 1844, p. 147).

http://atilf.atilf.fr/dendien/scripts/tlfiv5/affart.exe?19;s...