Factory Floor, where to find?

I am trying to get all of the items in the game (again) with the new items added.

I noticed something called "Factory Floor" in the all item list.

This does not appear to be craft-able. I found something called scrap floor, which is craftable, which kind of looks like a factory floor. I tried to remove the flooring inside the Scrapyard Incursion boss arena, but things inside there are unremovable.

Any insight?

Also, there are some items that you can place inside settlers apartments to boost happiness, such as the unmeltable ice. These do not appear on the all items list. I did an incursion that was supposed to give unmeltable ice as a reward but it did not.....I will see if I can find another tablet with this as a listed reward, and see if I can reproduce the issue.

Thank you.