Should I recap my speakers? If so who can do it?

I beg to differ on the sand cast resistors

It depends on the implementation. MRA resistors are wire wound and designed to minimize reactance at RF frequencies.

If the original design was tweaked to include the resistor reactance, changing them could make a difference. Whether that difference is perceived as better is totally subjective.

Capacitor upgrades from 'lytic and mylar to polypro trump resistor changes six ways to Sunday.

What works well in one design may not in another. There is no free lunch.

Agree with you.   No problem with anything you said.  

How do you know if your caps are bad? I assume visible leakage would be a clue. What if they look OK? I have a set of Snell Type A V5's. Kevin Voecks went crazy with large outboard passive crossovers. They were built in 1996. It seems to me that streamlining them could be for the better. Opinions please. Thank you. Joe

Age is a factor for electrolytic caps. Industry standard life is 15 years. Even if capacitance is still within spec, ESR is probably quite a bit higher than when new.

Polypropylene caps usually sound much better than electrolytic or mylar.

Replacing 20 year old mylars with modern polyprolylene can be a revelation.

Film and foil are preferred, but more costly. High quality Metalized film work very well and represent the best bang for the buck.

Be aware that capacitor 'reviews' seldom take into account contributing factors and are valid for that equipment only colored by the reviews predilections and prejudice. As always, Your Mileage Will Vary.

Quite right, ieales.

To comply with your concern, I initially experimented with an ESL based vinyl system, and classical music. This has since been upgraded to air bearing TT, etc. Current impressions are consistent with the formal experiment detailed above (I DIY all my electronics, and experiment continually).