Hi Simon,
Perhaps you should know that there is an opinion (mine) saying that the light metering design of the Oly SP is a disgrace. I have wrote about it several times so the neighbourhood may be quite tired to hear it once again. So I will be very short.
The scale in the viewfinder indicates Exposure Values, that in order to know what are you doing, you will have to take your eye out of the viewfinder, adjust the aperture and speed rings and then have the full range of options available. All these equals to a relatively slow manipulation, that in my personal case stress my nerves. The other use you can have is just to know you are not off the limits. Then, the other use of the auto light metering in the SP is the Program. But this is a very specific program favouring aperture at extreme costs regarding speed.
As for the spot metering....hmmm, well it gives you some correction over the general reading, but hardly it can be compared with the spot metering of the OMs, or a spot meter. It gives you something, it is true, and something is better than nothing, but it is not a big deal which is out of your imagination.
All in all, I would say that concerning light metering, with a simple and cheap Konica Auto S2, or a Canonet, you are much more better off.
Fine, this opinion is very much controversial. But at the same time this opinion tells you can enjoy very much the SP disregarding its light metering features. The optics are among the best Olympus manufactured. And since this is a high quality camera that lasts, the lack of a proper light metering system, even with the cameras that it is working, like mine, should not stand in your way.
Now, I am not among the dexterous beach boys who can do without a hand meter. If you are like me, I urge you to leave aside any repair of the Oly meter and buy instead a small Sekonic digital meter, which will enable you to use any meterless camera, and will enhance the capabilities of any built in meter camera you may have, with the incident white dome no camera has.
The combination of a Sekonic digi and the Oly SP, is a first class winner.
Cheers,
Ruben