Gentlemen, thank you for your rapid and informative responses! Drew, what I meant about the birds was that there are one bird in a circle on each lock plate side. The bird in your photo, as well as the surrounding engraving, looks almost identical in placement and style to my left side lock plate. The bird on the right side lock plate has a long pointy beak. I posted many photos on Gunboards in the shotgun forum (with 50 views and not a single comment) before I found this forum.
Here is the link (I hope that's OK):
https://forums.gunboards.com/showthread.php?1135727-Need-help-ID-ing-LC-Smith-model-grade Thank you!