Nothing has moved sharply since the last time I wrote, which is worth saying plainly rather than dressing up. There is £148,400 in the account. £56,500 of that is VAT and corporation tax, so £91,900 is actually yours, against the floor of £60,000 you set. The VAT payment of £21,900 is due in 23 days and the money to cover it is already in.
The thing that has changed is the shape of the book rather than the size of it. Marsden Group is now £112,000 of what you are owed, 38% of the total. Two quarters ago it was under a fifth. That is not a problem today and it is not a reason to do anything dramatic, but a business where one client is more than a third of the receivables has a different risk profile from one where the largest is a fifth, and the change happened without anyone deciding it should.
Marsden also stretched from 26 days to 41 over the same period. Growing concentration and slowing payment in the same client is the combination worth watching, because it means the exposure and the delay are the same phone call.
If I were you I would not chase Marsden. I would spend the next quarter making sure the second and third largest clients grow faster than they do.