seryn

Standard dictionaries are unlikely to tell you this in any detail--"wright" is the person who has wrought something, literally, and thus "wright" is a back-formation from the old spelling of a form of "to work" (OE wyrcan or wircan, depending on dialect area, and those initial vowels weren't quite the same then). By the fifteenth century, perhaps under influence from Dutch and Flemish industry in London, the simple past-tense form (preterit) had shifted from "worhte" to something closer to continental German forms, and thus we now have "worked." "Wright" and "wrought" were left as fossils, which is one reason you're having trouble connecting *wrighting to anything: "wrighting" was never a word because the -t encapsulates a finished product (something worked, the way that iron or wood can "be worked" to create an aesthetic object). Something like *wirchende wouldn't occur to most English speakers without historical awareness, but it's a viable earlier spelling for "working."

And yes, "wain" is a wagon: soften the -g- towards -h- and you'll hear that they're originally the same word. The Big Dipper was called the Great Wain for a time.

Half this game is knowing the sounds that certain sounds can become in other contexts (like the -g- / -h-), and knowing when they're unlikely to shift to any other sound. I could go on, but I'd better get back to work.