Yep....This.....if its an adv you are confident with....1L at a time..empty darkstar...lubrisolve are quite cheap for bottles and their postage is reasonableDoes it need to be plastic & nibbed?
Boots Glycerin as VG and then use the empty is what I do a lot.
It is glass and needs decanted to plastic bottles if you have them.
I have actually progressed to using the empty 1 litre bottles of PG from Darkstar