Great feature of 'most' prewar Model 70 model production, the integral front sight ramp! Chopping as to suggest "originality", typically requiring precision welding restoration. Known nowadays to be done, but look for rare chamberings $$$ justifying. Factory integral occurring with 'very early' production target Model 70 genre. Themselves, high collector value.
Also, the "never say never" in terms of Factory custom orders though without substantial provenance, "to buy the gun, not the story!" In respect of a 21" barrel, just the personal opinion, except as found in metric production rifles, numerically 'odd' numbers, between 16" & 30", extremely uncommon in 'other than' altered. Saying such, bowing to Winchester 375 H&H @ 25", as 'exception'!
Just my take
Best!
John