Incom's is famous for making several prized vessels. The T-47 Airspeeder, the T-65B and T-70 classes starfighers, a.k.a. X-wing class.
Sometime in between the production of the T-65B and the T-70 models, Incom was approached by the M:tron Mining Corportation with the need for a vessel that would both be a part of the everyday mining operations as well as the mine's main defense against incoming asteroids.
As a result, the T-65:M was developed. The most significant features are a shorter nose (the vessel is 15 studs long, the wings fit within the 16-stud limit in attack postion) and a reduced performance to keep the costs as low as possible.
The four lasers on the wingtips function as powerful tools to help to blast the boulders that normal excavators can't dig past. They are also just strong enough to reduce asteroids to dust but not much more. Keep in mind that M:tron has a clear anti-weapons policy.
The four engines are only slightly modified versions. There is no hyperspace drive needed so the engines can be both smaller and are more economical.
Because there usually is no air on most dig sites and miners need compressed air anyway, M:tron decided that pumping air into a cockpit is a waste of precious air. This resulted in a more open cockpit which also provides some much-needed cover for the astromech droid.
The pilots need to have the reflexes of swoop drivers before they are allowed to navigate those narrow mining tunnes.
The typical and feared X-wing silhouette was kept in the hope of keeping Blacktron away.