You need to work out which Veloce 10-speeds you have. There have been at least Powershift and Ultrashift, and possibly more. That will, I think, affect parts availability. Posting clear pictures of your Ergos, especially from the front of the bike (which is the view that most obviously differs), would be a good start. Are there any markings or model numbers?
Campagnolo do exploded diagrams in the form of parts catalogues. Don't filter to Veloce, because the catalogues are annual and cover all models. Ergos are typically in part A for each year, but it can vary. Generally best to know first at least the approximate year of your model.
Once you know your part number,
Mercian are good for Campagnolo spares. I believe they will also offer advice if you ring them.
Chicken (use the filter by manufacturer),
PlanetX and
Fawkes are other options. So is eBay.
The models that can be serviced are not too hard to work on. The 9-speed ones I did came as a bag of bits because the previous owner had tried, using the wrong model of lever as a donor, and sold me a kind of 3D jigsaw puzzle after giving up - with bits from the casualty and the donor shifters all muddled up. I ordered the proper replacement body from Mercian, and I'm still using the result.