Can I use a 39-yard inner liner for 38-yard HV roller skates?

Yes, because HV shoes themselves 35, 36 are a size shell, 36, 37 are a size shell, and 38, 39 are also a size shell, so this exchange is possible, even for 37 and 38, because the top of HV shell is not a plastic shell, but a leather shell, so this exchange is completely possible.