personally. just about all old tractors I like to run 15w40 S/C rated oils. In arctic conditions, then a 10w30 C/S rated oil. The oils that carry a C ( and s ) are rated for diesels and generally can be a better oil than S only rated oils when looking at some addativs like ZDDP..e tc.
on the coolant, premix it and add, then roll engine over to fill voids and top off. not an exact science.. but it gets er' done.
what does your old oil filter look like?
is it an element or a screw on. if a screw on.. is it a weird screw on that looks like it has a flange like a mason jar lid? some alis chalmers and older case use a fram C159 screw on. ( My case VAC uses that filter as well as my alis G - it is an odd looking filter can stuffed with filter floss and usually has a stem mounted on the filter base that you need to watch out for when you remove the filter ).
As a 'general' rule of thumb. machines that have seperate compartments for diffy, trans and hyds can use gear oils in diffy and trans compartments, and UTF fluids in hyds. if hyds shares a compartment with trans or diffy, then use a UTF in the compartment that is shared with hyds, unless you know that the hyds is designed for gear oils ( some machines DO have hyd pumps designed with heavy mineral oil in mind ).
post back.