Learning to use new Tesoro Silver uMax; stuff found in the woods, including a whatzit

[jsandin]

Using a new Tesoro Silver uMax, I hunted two overgrown long-ago-demolished sites; a house and a school. It was tough to swing the detector in all the undergrowth, but I pulled out the following:
A dribble of molten brass or bronze (image 1 below).
A chunk of stuff resembling a cinder or a clinker. A magnet attracts it, barely (image 2 below).
A whatzit: An iron cylinder encased in a non-iron collar (images 3 and 5 below).
A play-money FALSA PECUNIA aluminum nickel dated 1950 (image 4 below).
A rusty 1927 railroad date nail (not shown).
My experience with the Tesoro so far has taught me to ignore anything that doesn't produce a clear beep when swinging in two directions.
I'd like to hear anybody's idea of the origins of the chunk, dribble, and whatzit.

 

Amazon Forum Fav 👍

Upgraded Night Vision Monocular Digital Infrared Monocular Telescope for 100% Darkness with 8X Zoom - Grab it through Amazon!

[against the wind]

Railroad Maintenance Nail. They were used many years ago to monitor how often railroad ties were replaced. Excellent hunt.
Congratulations
Can you show a picture or 2 of the nail??

 

[trapperart]

Congrats on your finds. Your whatzit looks a little like part of an old foot dimmer switch for head lights

 

[jsandin]

ATW:

Here is the nail. It is a lot rustier than any I've seen, but I've never dug one.