You have to make the best of what you have and what you can afford. The TVS is top notch, but never had opportunity to play through one.
I think a few basic things are needed to get to the right sounds.
1. Correct echo timings and levels
2. Preamp sound and EQ
3. Boost.
4. Overall EQ (studio)
5. Vintage pickups and a strat.
6. Vox amp tone and correct settings.
The more of each of these ingredients you add , the closer you get.
The boost element is one that is incorporated into the TVS and some echo units provide a means to drive the echo and the amps pre amp. I have found that a good clean boost pedal does enhance the sound a lot.
I have tried several ways to do this and after much deliberation and gut instinct , I recently bought a Wampler Tumnus deluxe pedal. It is based on the Klon Cenatur which go on ebay for siliy money (£3000 - £5000)
Comparison videos on uTube put the Wampler very close matched.
Whilst the Tumus is an overdrive pedal , it is often used to bring out the guitar sound (boost) and does it in a way where it does not change the guitar sound other than to beef it up .
I tried it out at home and the club and the sound was so much better. So if you have a good sound it just improves it. The gain on the pedal does not really come in till around halfway , so it gives a lot of volume and saturation and makes it more juicy.
Of course boosting with pedals has been done for years with different results, such as treble boosters and Tubescreamers etc, but a clean boost that does not fundamentaly change the sound is desirable for Shadows sound.
The Tumus is great at boosting without changing your core sound. I am pleased with my finding and it helps out with other echo units in my view.
I bought the deluxe , but they do a cheaper model in small footprint. It's my 'always' on pedal now on