My First N04 Mk1 (Long Branch???)

[Sunray]

It was assembled out of parts bins with no QC whatsoever by Century Arms. That's what the CAI ST A VT(the ST V VT means Saint Albans Vermont) stamps on the barrel mean. Check the head space before shooting it. Century is notorious for assembling both types of Lee-Enfield out of parts bins without bothering to ensure the thing is safe to shoot.
Fortunately, if the head space is bad, fixing it on a No. 4 isn't the expensive nightmare is it with a No. 1 Rifle. There should be a number(0 to 3) on the bolt head. You can buy one number higher and try it with proper head space gauges. However, if the number is a 2 or higher finding a bolt head will likely be an issue. You can rent or buy head space gauges from Chamber Reamers, Headspace Gauges, and Firearm Accessories Since 1957 - Pacific Tool and Gauge or Brownells. No fuss at the border for tools.
For reason known only to them, Gunparts lists the No. 4 Rifle under SMLE on their site. Being in North Bay helps. Try Epp's in Orillia(they speak Lee-Enfield) or Western Gunparts(no online catalogue).
Firearm Parts - Hunting
Request Rejected