Hi, Pastille,
The McFlannells was a programme on the wireless, (the thing we listened to before radio was invented). They were the creation of Helen W Pryde, and all the characters were called after materials. The shauchly wee nyaff in question was Mr McMuslin. There were also people called McCotton, McSilk etc.
The story was based in Glasgow, where the family lived up a close. Approximate date, perhaps between the wars. Sarah McFlannell, the matriarch spent much of her life trying to make her husband, Willie, speak properly (pretty much like Mrs Pipesmoker's efforts with the one she is related to by marriage).
The books are out of print, but can still be summoned up on eBay.
Shauchly, I think refers to the person's gait. Probably one with bow legs, and who shambles along. That's how I described it anyway.
Worth a look if you get the chance.
P