Lamb weaning

Hi. We're in North Waikato and have had beef cattle on our small block for the past 5 years. We ended up with 2 ex-calf club lambs last week and I'm looking for weaning advice. We're new to sheep and getting confused with all the different advice.
We've had the lambs for 1 week and they're now apparently 9 weeks old. We kept up the feeding regime the previous owners had them on: each lamb getting 2 feeds of 300ml of Anlamb (70g of powder) and about 150g of Lamb Start Mix pellets/day. Though they haven't always had the pellets. Plus grass which they seem to be happily nibbling away at.
They came to us at 16.4kg (male) and 16.9kg (female). Just weighed them and they've both gained exactly 2.5kg in a week.
I read on a forum here that 1.5kg gain in a week was good. And to wean from milk at 20kg.
Advice on what to feed from now and how much...keep up the same regime for a bit longer/drop to one feed of Anlamb a day and be more regular with the pellets?? Other options?
Thanks sheep peeps !!

That is the sort of suggestions that I give. We have tried weaning at 9 weeks, and the result was disastrous for the lambs. We wean at 12 weeks or 20 kg, whichever comes LAST. The amount they are being fed is very small for 9 week old lambs, but the grass is currently very good quality, which probably accounts for why they are putting on so much weight with so little food. Also your property will not have any sheep worms on it, which will also help to reduce wastage. We usually have to open an extra bag of milk powder to get the lambs to 20 kg and 12 weeks. The left-over powder gets frozen to use next year.

Interesting. I went into the vet clinic on Friday to ask about drench and the woman at the farm counter was horrified at how much we were feeding them (ie that we were massively over-feeding them!!) and said they should have been weaned already. Hence our confusion as we thought we were doing ok!
Though we've had issues with another non-vet staff member there in the past telling us what the vet had prescribed was a waste of money. *sigh*. Didn't listen to her then, shouldn't have listened to this one now I guess.
So you think definitely keep up with what we're doing for another 3 weeks. And be more regular with the pellets? The 2 milk feeds are 300ml each feed for each lamb. Not sure if that was clear in my original post...

After many years of trying to work out the correct amount of powder, we do 3 feed 50g powder, 250g water (weighed on the same scales - very important when they are young) three times per day, so 150 g powder per day compared to your 140 g, so close enough. We used to weigh lambs with a bathroom scales. Put the scales in a big plastic bag. Catch lamb and stand on the bag part of the scales to weigh both the human and the lamb. Remember the weight. Get off the scales, let lamb go then get back on scales. Subtract human weight from total weight equals lamb weight. You need two people, because the person holding the lamb cannot see the scales reading.