I seem to have got into some confusion with my review of Blastfighter.
According to this it seems that the banjo player in Blastfighter is Hoyt Pollard, who is also credited with playing a boy in the gas station in Deliverance. However it seems that the banjo player in Deliverance is credited as Billy Redden. 
The actor playing the banjo in Blastfighter though does seem to look like the banjo player from Deliverance. Maybe just coincidence. The connection between the two films still remains though, as Blastfighter could not be any more Deliverance even if it had cast Jon Voight in it, which it of course didn't.
There is some banjo boy confusion related discussion here and here is an article that attempts to explain the confusion.

