The top of that column may be quite unrelated to the rest. As we lack more info from the situation and surrounding findings, inferences are also limited for the first two carvings.
But those other two need to be rotated. Then we see a bas reielf for a blacksmith or even locksmith:
Whether it is from funerary stele or a 'shop sign' seems an open question without further details.
A site specialising in Roman locksmiths uses a variant of the above image for
And finally, I'll show that famous image from a locksmith's grave stone, now in the Aquileia museum, that actually shows Roman lock makers at work! Note especially the completed door lock on the lower right. The bellows and tools: hammer, tongs and file, are immediately recognizable, and remain much the same for the next 1500 years and more. Notice also the design oŁ that little furnace, made like a miniature temple.
To the right are tongs, hammer, a spearhead and a lock.
The picture I used is credited with:
Relief depicting a blacksmith's shop and tools (stone), Roman, (3rd century BC) / Museo Nazionale d'Abruzzo, Aquila, Italy / Giraudon / The Bridgeman Art Library