The NLS mapping website is great for comparing modern maps with various geo-referenced historic maps - including old estate plans.
The side by side map option allows you to compare any combination of maps/imaging:
Tip: If you select an "OS Six Inch" or "OS 1:2,500" version from the list of map layers you get the detailed local Ordnance Survey maps from the 1840s onward.
Also, a few years ago NOSAS (North of Scotland Archeological Society) in association with NLS and Lovat Estates undertook an effort to scan the old local estate maps. They are all available at NLS and this is the one that covers Fanellan:
Canmore is a searchable online catalogue complied by Historic Environment Scotland and which shows dots on their mapping for sites of interest. The link below is for a local map search:
Ambaile - Highland History & Culture website is another searchable multimedia catalogue and although no particular Fanellan results there are lots for Kiltarlity (see link below) which include our community/Hughton: