Peach leaf curl

When I moved here there were two dwarf peach trees. They have generally been susceptible to peach leaf curl, and I suppose that's the reason that one tree died. The other seemed to die, but sent up shoots from the root area and now is alive, although not doing too well. Still, I got maybe 3-4 quarts of little peaches each of the last two years or so.
We had an exceptionally rainy spring here in Berkeley, CA this year and the surviving dwarf peach tree has terrible peach leaf curl. Almost all the leaves are yellow and badly deformed. The only leaves that look OK are very small and rather rare. I've never treated the tree, although I have a plastic bottle of Chacon Bordoil copper-oil fungicide that I purchased some 20 years ago (and never used).
So, my questions are:
1. Is this Bordoil peach leaf curl treatment still usable, and is it a wise choice for treating the condition?
2. Is it at all possible to do something to alleviate the condition at this point in time, or do I have to wait for fall or winter?
Thanks for any information.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.