The UV set for the pole of the bell floor version starts at 1 and ends in 16, resulting in 15 pixels over 1 block distance.

as seen in the picture the stone pixels from the bell are slightly larger then the pixels from the stone next to it

the bell_floor.json just has to be replaced with:
{
"textures":

{ "particle": "block/bell_bottom", "bar": "block/dark_oak_planks", "post": "block/stone" }

,
"elements": [
{
"from": [ 2, 13, 7 ],
"to": [ 14, 15, 9 ],
"faces":

{ "north":

{ "uv": [ 2, 2, 14, 4 ], "texture": "#bar" }

,
"south": { "uv": [ 2, 3, 14, 5 ], "texture": "#bar" },
"up": { "uv": [ 2, 3, 14, 5 ], "texture": "#bar" },
"down": { "uv": [ 2, 3, 14, 5 ], "texture": "#bar" }
}
},
{
"from": [ 14, 0, 6 ],
"to": [ 16, 16, 10 ],
"faces":

{ "north":

{ "uv": [ 0, 0, 2, 16 ], "texture": "#post" }

,
"east": { "uv": [ 0, 0, 4, 16 ], "texture": "#post" },
"south": { "uv": [ 0, 0, 2, 16 ], "texture": "#post" },
"west": { "uv": [ 0, 0, 4, 16 ], "texture": "#post" },
"up": { "uv": [ 0, 0, 2, 4 ], "texture": "#post", "cullface": "up" },
"down": { "uv": [ 0, 0, 2, 4 ], "texture": "#post", "cullface": "down" }
}
},
{
"from": [ 0, 0, 6 ],
"to": [ 2, 16, 10 ],
"faces":

{ "north":

{ "uv": [ 0, 0, 2, 16 ], "texture": "#post" }

,
"east": { "uv": [ 0, 0, 4, 16 ], "texture": "#post" },
"south": { "uv": [ 0, 0, 2, 16 ], "texture": "#post" },
"west": { "uv": [ 0, 0, 4, 16 ], "texture": "#post" },
"up": { "uv": [ 0, 0, 2, 4 ], "texture": "#post","cullface": "up" },
"down": { "uv": [ 0, 0, 2, 4 ], "texture": "#post", "cullface": "down" }
}
}
]
}