Since trains are mainly drivern based on visual indications from outside the cab, having a good view forward is crucial to being able to drive properly. On the other hand, gauges are secondary, even the speedo is only there as a cross referance against what you can see and hear, and many steam (and early EMUs) didn't have them, infact the most important gauge is usually the brake pipe gauge, particularly with none self lapping brakes (those with release-lap-apply positions, rarther than proportional notchs). Other gauges are of very little importance, and infact most gauges on a steam loco are for the benefit of the fireman, not the driver. I'd say the best driving position for a BVE steam loco would be to have a view of the track straight ahead, either through the window or head-out, with main gauges (brake pipe and speedo) to the right hand side. Remember, the scrolling view of BVE 4 allows the viewing position to be moved, and on a steam loco this could be particularly useful.