cleave mcneil on the u s army enlistment is correct he is the grandson of john mcneil and margaret clucas and son of cleave mcneil and jane kelly,on the form on ancestry it shows him enlisting on 7th jan 1888 and being discharged onjuly 14th 1888.
after that i found a c mcneil on new south wales , australia, unassisted immigrant list , born abt 1863 age 27 port of departure melbourne port of arrival sydney, new south wales, voyage arrival date june 3rd 1890 on a vessel called konoowarra, and it says he is british. i wonder if he went to australia , but i cannot get any australian info and the death in texas is not him, any help appreciated