From a fellow Douglas wearer (Ancient tank and modern PV 8 ydr) and Douglas sept clansman, you are looking good. I really like the large sett which is shown off by the dominant white line. Sounds like you got a pretty good deal. From the looks of the selvedge you probably got either Batley, MM Jura or HoE Nevis material, as that looks like the rapier cut finish they all have.