These are not bad at all. Perhaps lifting the middle range ever so slightly to make them stand out better?
Silver Effex has a bewildering array of settings and I guess one has to experiment quite a lot to make the most out of this plugin. I paid good money for the Nik collection a few years back, but didn't have much time to learn to use the plugins (or standalones). Now, when the collection is free to all, I'm using it more ....