Gold? Or gold filled?

How can I tell?

By the markings. Most old watches were gold filled. If you have a 10K or 14 K or 18 K watch it's worth lots more.

Here are photos of marking on the first two cases.

20 and 25 years indicate the probably durability of the gold plate and was used before 1924. All those scratched in marks are from a watchmanker and indicate that he serviced the watch.
See the link.
http://www.pocketwatchrepair.com/how-to/case-material.php

The third watch may be more valuable than the one above it. I can't be sure from these images, but it appears that the last 5 spindles of the time chain are mounted in jewels. A jeweled escapement chain increases value. Jewels on the tips of the escapement verge contributes to longer life, lower friction, and higher quality.

Here is another photo of the third watch's innards.

Those pinkish things around the spindles are likely sapphire bushings (jeweled). Magnifying this image reveals the words "17 jewels" This watch is above average. If the hair and power springs are in good shape, A cleaning and lubrication may return this one to service for another 10 to 20 years.

Power springs are made of high carbon spring steel, are highly stressed when fully wound, and therefore subject to corrosion. If this part needs replacing, it would add considerable labor to the restoration cost, but might be worth it.

If the watch is disassembled for servicing, replace the seal around the stem.,

necrospam (ETA: now removed)

Have been having more and more postings of people who receive a commission per link in several of the forums. They almost always select a old thread to do their stuff on.

Any way to stop it?

Just flag it when you see it.

Okay, thanks.

Just needs another flag, then.