Good question....Let's start the discussion with some...

Good question....
Let's start the discussion with some information (for check please).

S32's Australian Manganese operation is entirely its 60% of GEMCO (ie 40% is owned by AAL).

All below are S32 share.

Expected Annual Production (S32 share) for FY24 and FY25 (before the cyclone Megan damage) was 3,400 kwmt (per half year report).
Expected Operating Unit Cost for FY24 (before the cyclone damage) was US$2.15 /dmtu, FOB (per half year report).
Capital Expenditure - Safe and Reliable - for FY24 (before the cyclone damage) was US$55M (per half year report).
Capital Expenditure - Improvement and Life Extension - for FY24 (before the cyclone damage) was US$30M (per half year report).
Underlying Revenue H1FY24 - US$318M (cf US$355 for H1FY23)
Underlying EBIT H1FY24 - US$67M (cf US$149 for H1FY23)
In H1FY24, underlying revenue was US$318M
in H1FY24, underlying EBITDA was US$125M, implying H1 operating costs of US$193M.

All someone has to add for info now, is re:
a. cost of cyclone damage repairs - gotta be US$200M+ as a guess
b. costs of sustaining site until operations re-commence - my initial guess would be that these costs might run at half "normal" operating costs ie around US$100M per 6 months
c. sales price effect - Mn price fluctuates - Ore grade sold is around 43%Mn - I don't have any useful data here
d. mine life multiplier - noting that half year report says that "the Eastern Lease South Project is expected to sustain production to at least FY28, with further work underway .... to potentially extend the operation's life into the next decade" - so real questions about longevity.

So, go for it someone.

S32 share can produce annual EBIT of US$300Mpa (at H1FY23 prices and costs, give or take big price effects), but from when, and at what restoration cost, and to what end date.
Lots of parameters for the analysts and negotiators to work with - LOTS!

First cut - US$300Mpa for 4 years life gives US$1200M total EBIT, subtract US$300M for repairs and delay costs gives US$900M value for our 60%. So US$600M for the other 40%.
Of course if you take a different view on price or mine life or restoration, you could get a significantly different number.