If your going to invest in a new set of laps I would recommend getting a set of 8” laps. Having a much bigger surface area to work with is far better.
One plain aluminium (Australian spelling) master lap, don’t get a one with the magnetic layer on top, they’re a pain to use. Set of bonded diamond laps, they’re about a millimetre thick and go on the master lap as required.
Don’t get the ones with the sticky back, as for grits I have 180, 360, 600 and 1200. Two Batt laps, one for 3000 grit and one for 50k diamond powder. Keep them away from each other, every time you handle the 3000 grit lap wash your hands before touching anything else.
I’ve found diamond will polish anything but Quartz, some guys may be able to polish it but I’ve never had any luck. So I use a hard plastic lap with cerium oxide, having plenty of pressure on the stone seems to work best.
Have a Darkside lap and a stick of Zirconia for Quartz, but found cerium the best.
When charging the Batt laps I only use 2 drops of baby oil to mix with the diamond powder, have found Diastik’s slower so don’t use them.
You will get a lot of advice on the forum as to what oil to use on the Batt laps. Baby oil is perfect for the job, it’s cheap and one bottle lasts a lifetime.
Hope that covers everything.
Frank.