Originally Posted by T-Mar

It's strange that it has a Kuwahara headset but not their serial number format. Based on the serial number, my leading candidate would be a frame contract manufactured by M-a-t-s-u-s-h-i-t-a- (Panasonic brand) very late in a year ending in a '9'. . Apollo was around in 1969, 1979 and even 1989 but we can probably eliminate the latter, as 6 or 7 cogs would have been normal on the back by then and I doubt the previous owner would have downgraded to 5 cogs. The other components aren't much help, as it's obviously been rebuilt over the years. Pending pictures, we might be able to increase our confidence one way or the other based on frame features.

Rear dropouts: short, long or vertical?
Brazed-on gear shift bosses?
Brazed-on bottle cage bosses? If so, how may sets?
Brazed-on pump peg?
Brazed-on front derailleur hanger?
Recessed or exposed brake mounting nuts?
Rear brake cable housing attached to top tube with clamps or running through brazed-on tunnels?
Gear cables running over or under bottom bracket shell?

BTW, I used to know Lorne "Ace" Atkinson. Back when I started competing in the early 1970s, he was one of the much respected elder statesmen of the Canadian bicycle racing fraternity (though he only would have been about 50), having been a big name in the post war period and a national team coach.