"...303 autoloader looks interesting...commercially bubba'd SVT 40..." Yep. 7.62 x 54R ammo was not available, at any price, then. Globe tried to make the SVT work with .303 British. The conversion was so poorly done, most of 'em had bad headspace.
"...that was a lot of money back then..." An astronomical amount of money. Pay scales were a lot lower. In 1970, Alberta's minimum wage went to $1.55 per hour from $1.40, in October of 1970. Ontario's was $1.50 per hour. Up from $1.30. $359.50 was 6 week's gross pay.