Datasheets never give M, it's a rather useless figure, it arises from physics but you never measure it in circuit.
Hmm, well I suppose you can, since the definition is:
Vp = Lp * dIp/dt (single inductor, Vp = primary voltage, Ip = primary current)
Vs = M * dIp/dt (coupled inductor, Vs = secondary EMF, Ip = primary current)
You'd apply a constant AC current to the primary, and measure the secondary current. M drops out from the secondary, while Lp drops out from the primary (and if you apply the current to the secondary, you measure Ls instead).
Anyway, you're more likely to measure Lp, Ls and k (coupling factor).
https://en.wikipedia.org/wiki/Leakage_inductanceLL is easily measured by shorting one winding and measuring the other winding inductance. LL, k, and M (as a product of Lp, Ls) are all easily related.
Since they don't give any of k, M or LL, it's impossible to know them, or Ls exactly. Presumably, Ls is around (10/1)^2 * Lp, or 2500uH.
Incidentally, you use the inductance ratios in SPICE, not the turns ratio. So to model this, you need to enter the inductances accordingly, and put in a coupling statement ("K12 L1 L2 0.98", say).
Tim