If we use these similar but tweaked figures for 2019 things will...

If we use these similar but tweaked figures for 2019 things will look a whole lot different, fully ramped up including fines and constructing another DMS.

From the FS:

Net cash costs are expected to reduce to under A$400/t if an allowance is made for mining and crushing of stockpiled screened fines and middling concentrates containing about 25% of mined lithium were to be processed. The fines and middlings are likely to be treated via a floatation circuit (LFC), however test work is incomplete and the LFC was excluded to reduce initial construction time and cost.

Mining currently accounts for more than 50% of cash costs. It is likely that larger mining equipment will be selected for bulk waste mining and when final pit limits are determined in pit waste rock disposal into earlier pit stages will be adopted to reduce haul distances. Larger equipment and in pit waste disposal is expected to reduce unit mining unit costs.

$1115 - 325 (Cannaccord figures, I thought I read $310 somewhere but cant find it) = 790 p/t multiply by 250ktpa gives $197M @ 30%
= $138M with TAW share being $69M (add 20% to this, total $83M, if you believe 300ktpa is achievable)

300,000 pounds TA at $90 pound = $27m or $18m after tax and $9m for Tawana.

Total 2019 approx $78M with a PE of 10 gives $780M MC ($920M at 300ktpa) - X3 in 12-15 months.

Production doubled in 2020 but maybe/maybe not fully ramped up until early-mid 2020 and your looking at $1.55 - 1.85B MC, X6-7 current SP in two years.

A lot of factors such as lithium sentiment, market sentiment etc which could dampen or enhance the above figures amongst many other risks.