Help dating two dresses

[westfirst]

I purchased a lot of clothing that belonged to a 80-something year old lady, her mother and grandmother. So much awesomeness there! I am still not the best at dating dresses, so I thought I'd get your input.

Here is the first, this was her mother's wedding dress. I believe it's 1920s? What confuses me is that the side and shoulder seams are serged (pictured). However, one source I have says that serging was used on clothing as early as the 20s. There is also machine sewing and possibly some hand sewing. If I'm going to list this, what are some terms to describe the lace/netting material, also what are the flares at the bottom called. Finally, should I clean this or leave it to a professional? The fabric is sturdy and the coloring is consistent, there is no staining. Can I steam it?

Front

Bottom

Slip

Serging

Next, I believe this dress is silk satin??? I think it's been shortened as well as repaired at least a couple times (patches on elbows as well as one waist tie.) There are snaps (is that the technical term for them?) down the front of one side to the waist. How can I clean this dress? Overall, it seems to be fairly vintage clean, but there are a couple spots of dirt/food? Should I spot clean this? Can I iron or steam it?

Back

Front

Snaps

Thank you so much for your help!!!

 

[Jonathan]

They both look like they have been altered a lot. The lace dress appears to be a 20s dress that was redone in the 30s. The lace on the sleeves, neckline and stitched across the bust are different from the rest of the lace and you don't get that type of mixed lace use with this type of lace in the 20s. Also, the slip is 30s. The black dress also looks like it began life in the early 20s but was redone in the 30s. Its not uncommon to find 20s dresses altered for the 30s considering the economic climate of the time. If they were mine, I would steam them, present them nicely and sell as a lot - examples of early 20s clothes that were remade in the 30s.