This will be easy. The Solen is a fair capacitor and was the industry standard about 20 years ago. During the past 20 years other capacitor manufacturers have improved dramatically. I haven't tried the TRT, but have tried the AuriCap and Sonicap. Both Auricap and Sonicap are much better than the Solen, and about equal sonically. Either better capacitor would be a darn smart improvement over your Solen Capacitors.
I suggest you use the same method I used when swapping capacitors in my CD player. While this is not the most scientific, it's very practical. Find all the Solen Capacitors and replace them with better capacitors ( I used Sonicaps). The reason for my method is simple.
The source gear manufacturer chose Solen capacitors in the critical locations and cheaper elecrolytics in lesser locations. Following the manufacturer's thinking will work just fine. Those manufacturers don't waste any $ on parts.
A more scientific method is to find the coupling capacitors and swap only these. This is simply because they are the most critical. If finding these capacitors isn't possible (true for most folks), then resort to the non scientific method. Replace all the Solen capacitors with equal value & voltage better capacitors.
