Al,
I understand that there are no set "rules" when it comes to Maynards.....

Your wonderful, new .40-60 has the "round full length barrel", "checkered stock of fancy branch walnut" with wide shotgun butt, and the extra tall patent rack-and-pinion rear vernier sight - all common to the #14 Creedmoor Rifle...which was normally chambered for the .44-100. The Maynard Mid-Range #13 was chambered in either .40-60 or -70....but the ones I've examined usually had much plainer walnut, the standard buttplate, and the barrels were of lighter weight w/some octagon at the breech end. I wonder what Maynard model # your rifle left the factory as..... a special order #13 or #14 with an additional mid-range barrel?

Is that full-round barrel stamped with a rifling twist # underneath and just behind the hook? The heavy 32" full-round .40-70 barrel on my Maynard #9 (or #10?) Hunting rifle is stamped "25". just curious about yours for comparison....

Again....that's a wonderful rifle!

Added:
That long-staff Maynard patent rack-and-pinion sight has GOT to be incredibly scarce. I've seen a bunch of the standard ones.....but only a few of the long ones!

Finally took the 32" heavy round barrel off the slightly rougher condition # 10 Maynard in .40-60 thick rim and it does match the receiver by serial number and it is stamped "25" twist just behind the lug so I'm assuming it'll shoot better with lighter weight bullets?  I'm going to try the 300 grain .410" RCBS greasers in both of the .40-60's I have and see what happens.  I'm hoping to try some paper patched bullets in them both at some point ...