The US$185 million development has an after-tax net present value of US$405 million and an internal rate of return of 49%, with a 16-month pay-back.
Production in the first five years averages 211,000 ounces per annum at all-in sustaining costs of $551 per ounce, while over the life of mine average output is modelled at 133,000ozpa at $640/oz.
Speaking on a conference call, West African MD Richard Hyde described Sanbrado as a "very, very robust project" that is set to "get better" over time as exploration continues.
High grade mineralisation continues to be hit below the current reserves to 500m depth at the game-changing M1 South deposit, with further results due in upcoming weeks and step down drilling to be ongoing.
M1 South's high-grade ounces and West African's underground development plans for the deposit have underpinned a four-fold increase in the project's post-tax NPV to A$540 million from the previous feasibility work back in February 2017.
A financing package is expected to be in place by the end of the year, and while Hyde said the project was robust-enough to be entirely debt-funded, the board would be "pragmatic".
Meanwhile the potential for corporate action can't be ruled out, with capital markets firm RFC Ambrian saying this week Sanbrado was one of the most likely projects in West Africa to attract third party interest.
Sandbrado is within 20km of Orezone's Bombore deposit - where feasibility results are imminent - and even closer to B2Gold's Toega deposit, with another B2 deposit, Kiaka, about 50km away.
Interestingly high profile resource sector private equity firm Resource Capital Funds recently became a 19.9% shareholder in Orezone with an investment in March of C$34 million.
"It remains unclear as to whether RCF's interest is limited to financing the company's development or whether it wishes to participate in the project's local consolidation potential," RFC said.
B2 is considered in some quarters as an obvious potential consolidator given its track record of corporate activity.
West African started June with A$44 million cash.
Shares in West African were up 3% to 34c in morning trade, capitalising the ASX and TSX-listed company at $235 million.