Hey there, I would use the http://undeniable.info/pz/wiki/recipe.php?ID=2445 instead of the main wiki, it tends to have better or more accurate information, at least for most things.
A lot of the stuff you will need will need to be crafted from other categories(Punching bag being under metalworking and mine under stoneworking for instance).

I have found a few things like the pullies in random chests and I crafted the welding torch and gas tank (it is under the engineer tab, assuming you have the recipes).

But since you asked for the upgrade to "dark mine" specifically I will list them here.

6 x candle in holder( candle + candle holder, candle holder is made via smithing, candles can be found randomly, most often in giftstores, and made via alchemy).

12 x wood beam, you need a log, a saw and a sawbuck, crafted in the carpentry tab.

2 x lumber stack, find some in a warehouse or lumber yard, or make them in carpentry.

1 x plank barrier, made in carpentry

8 x steel beam, made through smithing, requires a steam hammer made through engineering and steel rods also made through smithing

1 x work gloves, pickaxe and shovel. All of these I found randomly in containers or on zombies, check that website for specific locations that may give better odds.

Thank you :)