Yes, Withworth are an Interarms trade name and used Zastava barreled actions. Charles Daly are also Zastava.
That's funny, because such guns have a collector value while Zastava itself are either "collecting dust" or serve as workhorse with no collectors interest...
Then, what we see here is that when these actions (Santa Barbara and Zastava) are stocked by others, they worth more and when it's done "in house" it's considered as low end...
Of course, the Yugo era stocks were not that great, with tinted wood, false rosewood, so-so sanding and generous gaps here and there... but at the end, they are the same-same barreled actions.