Owned and rented, tracked together.

One record per machine

Owned or rentedOwnership is a field, so both live in one list instead of two systems.
Due backA rental carries its rate, its period, and the date it has to go home.
Service datesLast serviced and next due, so maintenance is a date and not a memory.
Who has itAssigned to a job or a person, so nobody drives across the county guessing.

A drawing, not a screenshotAn equipment record, drawn simply.

Where equipment quietly costs you money.

Both are record keeping problems before they are equipment problems, which is why they belong next to the job.

Rentals that overstay
The machine that's been sitting behind the shop since the tear-off finished: the record says the day it should have gone home.
Service that slipped
Condition gets noted by whoever ran it last, so a machine going downhill is on paper before it dies on a job.
Rate on the record
Rate and period sit on the equipment record, so you can see what a machine is costing while it is out. Equipment cost is not part of the job margin calculation today.

One list for what you own and what you rent, with the dates that cost money on it.