Some of the BMX heads might know what this is, I recently pulled this out of my dad's attic, it was my very last BMX bike which we purchased part by part together, 50/50 back in the late 70's early 80's. He would help buy any part as long as I paid half out of my own pocket. Needless to say, it didn't get raced for more than a few months as I got my licence and she just hung in the garage collecting dust from then on.
For shits and grins I checked on eBay, these old 80's BMX bikes are pulling huge coin.
I'll have to snap some pictures of the rest but...
Very early serial numbered 1979 JMC Long Standard and first year fork.
Bullseye Euro BB.