Not an expert on off grid solutions, but I spent some time building mobile off-grid systems using solar, shore power (grid input) and LifePo battery banks.
The inverter you are looking for I believe is something like what Victron offers. Victron makes really nice stuff, super techy and customizable. This unit here is able to accept two AC inputs and has built in transfer switch. It’s a battery charger, inverter and transfer switch in one package.
https://www.victronenergy.com/inverters/phoenix-inverter-smart#pd-nav-secondimage
The only thing missing from this equation would be a suitable solar charge controller, which Victron also has plenty of offerings for. A plus to sticking with Victron is that your monitoring can all be done on one app. Some Victron devices also talk to each other and optimize parameters to extend battery life, favor off grid or on grid power, etc.
For battery banks, I’ve had good experience with the EG4 racks. They are power dense, have great BMS systems that are customizable, and are priced affordably. You can run these in parallel to increase your AH.
Lots of technical considerations go into selecting proper components, but maybe this will help get you started.
Valve cover gaskets are on the top or side of the engine, depending on the design and when they start leaking, they tend to soil the exhaust manifolds, which are one of the hottest external parts of an engine. That smell is oil vaporizing. It’s not uncommon for engines with some age to leak from several areas, including the valve covers. If you can smell it, then it’s a leak significant enough to warrant a repair.
As others have stated, the leak will slowly drop your oil level in the engine and if it gets low enough, it will starve the engine of its vital fluid. Engines need oil to protect rotating and moving parts from direct contact with each other. It also serves some purpose as a coolant. The engine oil needs to be kept clean and changed frequently to ensure these parts don’t wear prematurely.
It’s kinda cool, actually - some of these parts are suspended by a film of pressurized oil. The two parts never really touch each other, although they appear to be in direct contact. Thousandths of an inch or less separate them, and the oil takes up that space, allowing the parts to move and “float”.