I added MS International to the Thrifty 30 portfolio on Friday at 269p, the actual price quoted by my broker, deducting amounts representing stamp duty and fees from the portfolio’s cash balance.

The business looks too good, and too cheap, to ignore, but I’ve made that decision with even less information than usual. Some would say that’s a good thing. Most information is noise, but there are limits, and in the cold light of dawn I might have crossed the boundary.

MSI doesn’t maintain an investor relations website, or publish its annual reports in PDF format, and it only mailed me a copy at the fourth time of asking. Other investors, their interest piqued by my first post on MSI are still asking, so I’ve scanned it for them [you can download it here, but beware it's 39MB].

You might ask why bother with such an uncommunicative company. Because I favour unloved companies that fly below most investors’ radars, if you’ll forgive yet another military metaphor, that’s part of the attraction.

With only the latest annual report, I haven’t been able to calculate a long-term earnings yield, and judging by the 10 year PE quoted by Sharelockholmes of 16, it’s by no means clear I’d like it. MSI has grown profits substantially in recent years so by taking 2012′s profits as a typical value I run the risk that future earnings might revert to the long-term average. An average PE of 16 implies an average earnings yield, albeit a less sophisticated one than mine, of little more than 6%.

The annual report offers little insight into MSI’s businesses. One, forks (for fork-lifts) is not even mentioned. The websites of businesses like  MSI Defence Systems, Global-MSI, and MSI-Quality Forgings, provide glimpses of who some of its customers might be: a photograph of a petrol station forecourt belongs to Morrisons for example.

MSI started out a blind valuation challenge, and its morphed into a partially sighted one. I could ferret out more information, but it’s difficult. I’ve pulled the trigger because I’ve seen enough to feel confident its current earnings are probably sustainable, and you can only spend so long researching each company before making a decision, to buy or not to. In a thirty stock portfolio, research time is necessarily short.

There are no guarantees, but assuming this year’s profit is a baseline for coming years I’d consider MSI on an earnings yield of 10%, 15% gives me some margin for error.