Need help with gold jewelry

[mts]

First off, I apologize if this is the wrong forum. I considered putting it in the scrap metals forum but you folks seem to know quite a bit about the value of gold jewelry.

I'm trying to figure out how much these items are worth. I received them from my father in-law who received them as awards from GM for many years of service. He took them to a local coin/jewelry dealer who lowballed him on price. There are 5 pieces but the three pieces below are representative of what he received. I would be grateful to anyone who can add some perspective.

The first piece is marked 10k. The marked portion is obviously 10k. But is the clutch back and chain also expected to be 10k or would you assume that they are just plated since they aren't marked?

The second piece (looks like a bracelet??) is also marked 10k. Should I expect the chain to also be 10k?

The final piece (looks like a silver bracelet) is marked as gold filled. The marking is 1/20 10k. Same question: should I expect the chain to also be gold filled? I'm assuming that this is white gold even though it looks silver. Is this correct?

Thanks!

[mts]

Update on pic #2 above... I cut off an end link on the chain and filed it down. It appears to be solid all of the way through. So my guess is that the whole thing is 10k gold. Any advice would still be appreciated.

PS - The dealer offered my father in-law $96 for the whole lot. This included $68 for a class ring (not pictured) that is worth at least $140 without the stone. That only leaves $28 for the rest of it. If pic #2 truly is 10k solid gold all the way through then it would easily be worth $150+. Considering he offered about 50% of the true value on the class ring, that implies he thought the rest of it might be worth $56. If pic #2 is truly worth $150+ then one of the following is probably true: 1) I am wrong and the chain isn't really 10k, 2) the dealer was wrong about the chain, 3) the dealer knew how much the chain was really worth and tried to rip off my father in-law, or 4) the dealer didn't care to mess with it and just threw out a number.

[cyberdan]

I lost track of what was offered for what, but here is the actual value if all are really 10K (probably only 9.5 or 9K) with gold at $1489.70

pic 1: $27.86 (the 2 clips and chain look plated, try a magnet)
pic 2: $171.14
pic 3: $9.55

[mts]

Thanks cyberdan. I tested the clasps and chain in pic #1 with a magnet and they appear to be plated. So pic #2 seems to be the big score and the others are low value.

Thanks!