I drove my landrover with 15J for about 5 years and was a metal case spin on as earlier post.
Just looked in the 15J manual that I have and only shows spin on type.
If you message ma an email address can send you copy of the manual.
Only option is to search for one using all the measurements, or ask in the wanted section if any one has the spin on adapter available they are interchangeable with 12J 10J and 19J and probably even 200tdi.
This lad is breaking a 19J ask him for a price for oil filter housing only two bolts to remove it from engine block.
https://www.ebay.co.uk/itm/Land-Rov...382393?hash=item28525aecb9:g:Ti0AAOSwy~BaM8vm