Like you I couldn't find very much info on the bike, your post came up near the top in searches. My aim with this is to spend zero, I have a number of steel road bikes but this is my first tinker with retro MTBs since my childhood! I'll get it running then see what will work, but those blue...
Funny enough I just picked up the exact same bike today for a tenner, it was next to a skip on a drive. I walked pasted 5 or 6 times then I couldn't ignore it any more, it was shouting "rescue me" 😆. Mines not in quite as nick but I am missing a retro MTB in the collection. All stripped down...