Yes, small trademark on the left side, except there are some models where that is the normal location for the trademark. On a 29-2 it should confirm factory engraving, but not always. But, there's more to the story. There's factory engraving and then there's other factory engraving. The work done by the master engravers employed before, and some after, 1979 will be the most sought after and usually the most expensive. Around 1979 S&W contracted out a lot of their engraving to Italian engravers. S&W letters won't tell you where, or usually by whom, a gun was engraved (there are exceptions of course).
The Italian engraved guns usually sell for $2500-$3500 while those by Russ Smith, Tommy Freyburger, Paul Piquette and others will go for double or more, sometimes a lot more. Additionally S&W contracted to independent engravers such as Denise Thirion and their work is often on a par with the in house engravers.
There are many great engravers whose work will command prices that match or exceed S&W factory work who were never employed by S&W.
As RKmesa, probably the most knowledgeable and prolific engraved gun enthusiast here says, "the engraving needs to speak to you." If it does, buy it.
Here's a 29-2 which has a letter confirming it to be factory engraved. I'm pretty sure it is an example of Italian contract engraving from 1980. Price two years ago was a little less than $3k.
The second one is also a 29-2 but from 1965 and engraved by factory engraver Russ Smith. Note the lack of a logo on the left side. It cost a lot more than $3k.
Jeff
SWCA #1457