Well done Bored Saint. I think that is not an easy thing to do given it's at an inflection point. My thesis is that this is a high operating leverage business (a lot of their costs are related to capex and/or are fixed - i.e. their revenue jumped without a proportionate jump in employee expenses last year - so I'm hoping that assumption sticks) and as such, it's possible a higher percentage of revenue will fall to the bottom line in the future.
They have stated their investing in further capex to meet demand, and so growth may be higher than your projection (but it is pretty hard to read based on their public announcements). There are also opportunities outside of mining that aren't yet exploited. So mix high operating leverage, with growing demand, low debt and an OK price (it was a lot better 6 months ago) and I think it's a good bet. Offsetting that, is that it is a new business, the exchange rate is probably at the low end and that will offset profits if it rises and whilst there is potential to take the services outside of mining, it's another thing to do it.
To disclose, I own IRL and on SM, and it's been on a very good run (particularly the last few weeks!), so that is something to think about (i.e has this potential now been priced in?). The next milestone is the HY result and I'll be watching to see if the thesis I propose above is playing out and we can get more clarity on its potential.