Will a Long Term Sewer Gas Issue Mean New Drywall, Carpet, Etc?

[Bob Crane]

Looking at a 1950 4/2 bungalow REO. Realtor tells me there's an "unholy smell" like he's never experienced inside the house. They believe the main sewer pipe may have cracked inside the crawl.

I also notice from the pictures that the former owner removed all bathroom fixtures and I don't see anything capped, which I'm sure is a contributing factor.

This house has been vacant for close to 12 months in this condition.  Once the problem is identified and repaired will the smell go away?  Or is it more like cigarette and pets where every porous item in the home is impacted?

I have no problem pulling carpets and replacing.  I would also bid with the assumption that a full sewer line replacement is needed.   There's no money in this if it requires new sheetrock throughout.

Bathrooms are drywall and bead board.  Living, dining, and kitchen are plaster.