[morzh]

What was the voltage dropout across that transistor? 25V? (115V-90V)
If this is the case, and the worst I=110mA, then yes, , 2.75W without heatsink is not just pushing it, that is very well exceeding it.
115V is AC though. You need to know DC before and after the transistor.

I do recommend you measure exact voltages so you do not guess.
Here's how I would do it.

1. Take 1 Ohm resistor (could be small as 100mA will dissipate 10mW) and put it in series with the transistor (either right before the Collector or right after the Emitter. And it has to be right before the pin, NOT before the input capacitor or after the output capacitor: it has to be Between the input cap and Collector or Between the Emitter and the Output cap).
2. Put a Voltmeter across that resistor. The volts will be your current in Amps. 100mV will mean 100mA.
3. Put the Voltmeter between E and C of the transistor. Measure the drop-out. Or. Put the Negative lead to the Minusses of the two electrolytics (they are connected together) and measure the E and then C voltage; then record them and the difference.
Whatever is easier.

Then multiply the drop-out by the Current.

Of course you have to wait until the radio is warmed up and the Voltages have stabilized.