Three are Gewehr98s, and variations thereof.
The #2 rifle really catches my eye. The rollercoaster rear sight (Lange Vizier) is both an identification tipoff and somewhat rare, albeit at this stage of decomposition not particularly valuable.
The lack of a thumb relief cut in the left receiver wall narrows things down even further. What's on the right side of the receiver wall nails it, though.
I'd wager it's a Turkish Model 1895, with the signature original magazine cutoff left intact. These were often removed when the guns went through arsenal refurb to 8mm Mauser circa 1935.
The rollercoaster sights usually didn't survive this rebuild, either.
The import marks on the barrels lets you know they came in as surplus through Century Arms International (St. Albans, Vermont). That means they came across the pond fairly recently.
That V. CHR. SCHILLING 1934 K98 was one of the rarest contract 98 Mauser manufacturers prior to WWII.
It hurts my collector's heart to see these in such poor condition, especially since they were imported in considerably better shape, and not too long ago.
On the flip side, storing guns under a house, or on a basement floor prone to flooding, does nothing but help the prices of other surviving specimens appreciate, I guess...
