Odor in cabin

"Boat smell" is kind of normal on boats, but not mandatory.
I would rip out any and all old carpets to start with and don't replace them. Gross...
Mold and mildew usually sticks to the headliners, especially above shelfs and other areas where they are invisible or hard to reach.
Advice from friends who lived on a sailboat in Panama with extreme temperatures and humidity: Use a vinegar citric solution: Mix 50/50 water and vinegar, squeeze a lime and a lemon in the bucket, mix well, then use a wet rag with the mix and clean every interior surface including the ceiling/headliner.

I did the above on my boats in South Florida and it worked well.
Boat smell can also come from the bilge, the head (toilet) and the galley. (Kitchen)
With good cleaning, good maintenance and good ventilation, the boat smell will go away.
You can either run air condition 24/7, or install canvas shade above the cabin, with overhead hatches including bug screens, open 24/7 and 120 volt cabin fans going 24/7 for ventilation.

I have done all of the above, no "Boat Smell" but it takes work and elbow grease to get read of the odor.
(Clean the bilges, replace head discharge hoses, wipe all surfaces inside the boat with a chlorine rag, and again: Vinegar and citric acid, it will prevent the mildew from coming back for 6 months, or more)
Good luck.

We looked at a Silverton 43 yesterday and the smell of raw sewage just about knocked me to my knees. When I looked below deck the holding that was full. I mean like no air in the tang. Full and packing up into the pump out port and probably the toilets. When we return from our east coast boat shopping expedition, I'll make a post. It's been interesting.

Shower/AC sumps and sink/shower drain hoses and pans can be an odor source... and permeated sanitation hoses. Mold. Gross bilge. Et cetera.

Usually not much to do with boat brand. (Silverton, Marlowe, Carver, Fleming, whatever.)

-Chris

Replace all the nonpotable hoses with good seald Toilet and sewer piping !
After 20 year of the problem I did this and the problem disapeard !

Tricky. Sometimes you can get a (n electric) pressure washer wand in the crevices, and sometimes you can suck up the water with shop vac extensions. And/or sometimes the water will pool in an accessible place.

-Chris

Get an ozone machine, worth every penny. Do check all the above recommendations as well. Is your sanitation raw water or onboard water flush. I just change my whole sanitation system out, new toilets, hoses and fresh water flush. Made all the difference in the world.

how is it going now? checked the ventilation/air conditioner?

Keep us posted, this is a common problem with new owners and old boats.
(But not with Old Owners and New Boats.)
In a nutshell: Ventilation is King, but many boats are locked up tight to keep rain and critters/bugs out, then they stink shortly thereafter.
This forum is more about yachts, as in bigger boats and they are too expensive to let deteriorate in the sun with no airflow or no Air Condition, hence they are plugged in to 30/50/100 amp shore power with AC running 24/7 like a house in the South.
At anchor big boats run a generator to provide AC and electrical power for fridges, freezers, lights, TVs, etc.
If you don't want to run Air Condition 24/7 then ventilate the boat: Erect a canvas shade over the cabin and the decks, the canvas are called awnings. Then install bug screens over open hatches and in the companion way, then run a small electric fan to circulate the air.
I did just that on a 33 feet sailboat we owned for 14 years, no Air Condition.
But had to clean old mold and mildew with the citric solution from the headliner and hidden corners first, we were sneezing at night before we did.
First clean, then ventilate, smell be gone..