YearOne has this:
Has anyone used these? I like the part where it says it can be raised...but I'll have to call and ask if that means raising after you lower in case you change your mind.
Don't read into this this that these are adjustable springs. Once you buy a set ride height of +1, +1.5 -1, etc, it is basically set. It might change slightly with use and "settle" in, but to change it up or down after the fact would require a replacement set to be purchased.
Go to a local spring shop and add a leaf?
Yup, it can be that simple if you want a slight increase in rate and a slight increase in height. CP, technical moderator on here, often suggests finding an original main leaf, cutting the eyes off it and using it under the main leaf for the slight lift.