Re: maintenance free boat trailer hubs
It looks to me like someone cut the ends off an old rear axle and made it fit a boat trailer.
What would concern me is how it can ever be serviced? As in, where are the retaining clips located?
Did the hide them inside the now welded closed axle tube?
It more looks like a rear wheel drive axle shaft to me, most front wheel drive rear axles have dust caps and either cone type bearings with adjustable bearings or sealed bearings with snap rings.
What is the lug pattern and what size and thread are the studs? Many front wheel drive hubs will be metric.