No properly functioning postwar transformer needs to be upgraded to work with more modern whistle tenders. However, the copper rectifier disc can age out and fall out of spec requiring replacement. Either new copper rectifier disc or more modern solid state diodes can be installed to bring the whistle control back to life.
As for a power transformer, the 1033 is a loosing value proposition, especially with shipping factored in. An LW, KW, or ZW are much better propositions.
Since we are talking about transformers, it is always best to ensure you have proper circuit breakers/fuses and TVS diodes as discussed heavily on the forum.
