I thought I was having trouble with my inverter last year and started checking what it would take to replace but ultimately I was able to fix my problem, which was downstream of the inverter.
Since all the original wiring is there is should not be too difficult to install an inverter. The original inverter was probably 2000 watt which was probably a RV2012 Xantrex (also known as TRACE), which I find is plenty of power for me. I know others have upgraded to a 3000 watt.
There are two major brands that are normally used in an RV application, Xantrex and Magnum. Xantrex would drop right into place with minimal modification. A Magnum may require changes but is doable, people like the Magnum because you can by individual repair components if you have problems, while the Xantrex would probably have to be sent to a repair facility.
A new inverter will require a new display even if you stick with a Xantrex, but you should be able to use the same communication cable (looks like a phone cable but is wired differently).
There may be other things required depending on the model you choose.
I recommend doing some research. Here are a couple popular models
https://www.xantrex.com/power-produc...2v_newgen.aspx
https://www.magnum-dimensions.com/in...tional-vehicle
You will have to determine what other components you need such as the display, battery temp sensor etc.
Here is a link to a post discussing potential changes, NOTE, it has links to other posts with details on how to change>> post #11 is a good one.
https://www.irv2.com/forums/f115/any...er-447840.html
Do a search on the IRV forum using the box in the upper right corner.
As an option you could take a chance on just putting back in a used RV2012 inverter, Here are several
https://rvcomponents.visonerv.com/cg...-converters.pl