I cheated, found a place that sells concentrated tonkotsu broth, it was £20 for a 1L portion, very expensive but as it turns out, incredibly good!!!! I mean it is light years ahead of Wagamama and almost on Japan level, if the bowl above is 10/10, this is easily an 8, may be even a 9 once I work out the ratio to my liking.
It even has fat on the broth, I am satisfied and I can say this will do nicely as a substitute, vs slogging away for hours.