Thanks to all the replies above.
After persevering and trying different warm up approaches I'm not having any real pain any more. I assume my hands are getting used to the bass again.
Anyway, I still managed to get a quick trip to merchant City Music this week. I had a play on a Reverend sentinel and it totally clicked. The size, weight and balance felt right (after a couple of minutes) and the sounds were great. The fundamentals were massive and the voicing switch gives enough play for a range of tones.
I tried a Mercalli too which after the sentinel felt clear as a bell but lacked the bottom end weight. It had a great stingray like definition as well as a precision type tone. The Dub king kind of sat in between them sonically but felt pretty uncomfortable.
I'm wondering if the short scale stingray will be a good blend of the sentinel and Mercalli sound with a short scale feel? Any experience?
Anyway, I'm off to prepare adverts to sell everything I can so I can afford the sentinel before it sells out!