WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
The Hasimoto A-105 is more likely a substitute for the NC-14 (as the A-107 is with respect to the NC-16), and it costs a lot of money.
If you need a NC-10 like IT, perhaps you may use the Softone/ICL Audio RC20: even if it should be a drop in replacement for the Tango NC-20F, it also has a step down winding scheme aiming to replace the Tango #11643, a custom version of the NC-10 specially made in the past for "Nobu" Shishido.
Last but not least it should be cheaper than the current ISO-Tango.
Even Silk/SAC Thailand I-511S/P (another NC-14/16 equivalent) has better measurements than current ISO-Tango ITs, but it costs roughly the same money and it should be less flexible: maybe not a so good deal, and if in case I would rather the Hasimoto for sure.
Yes, the Hashimoto and other Japanese sourced iron is pretty expensive, no doubt the weak dollar... I know Hashimoto has had to raise their prices a bit in the past as a result. On the plus side, their products are excellent and you can get all of your iron in one-stop... power, choke, output, interstage, etc. They also have superb shielding and you don't have the worry of rotating and moving iron around to eliminate the magnetic coupling and resultant hum issues.... but that does cost.