Yes, it is.
Yes, it would be the correct switch.
Its listed as a 1.81"WC SPST PRESSURE SWITCH Carrier doesn't give many specs on their replacement parts.
Yes, HK06NB124 replaces part HK06NB119, which is obsolete.
The correct replacement pressure switch for the 58MXA120-F15120 is sku HK06NB124.
Yes, HK06NB124 is the recommended replacement for HK06NB120.
Yes, we only carry new and unused products.