The dust caps are inverted on the originals.
I have owned and listened to the 880 for about 8 years and I was very happy with them until upgrading recently. They replaced a stacked quad of JBL L100. It took a long time to find the parts to restore them.
The last time I listened to them, I had the urge to get rid of all the capacitors and replace them with affordable, bypassed polys. There are a couple of lytics that should be done at the minimum. I have not got around to this.
They large tweeter is turned back one notch on the l-pad and the ports are stuffed. The port should remain closed unless you are using a VERY low power amplifier. I have amplified these with the 2325, 2275 and SM-7. They are all great, but I prefer the SM-7.