miniDV tapes are deteriorating. Can't convert to DVD. Am I doomed?

I am beating myself up for not doing this early. Feel very guilty now, but want to act and save what's left of it.

Summary - have about 12 miniDV tapes that needs to be converted to DVDs. A decade ago, I was a pro in capturing miniDV tapes to desktop PC via firewire. Amazing quality!!

Then life happened and didn't touch video capture for the longest time. Times changed and no firewire option on new laptops. Old desktop met its grave. My reliable camcorder also died.

Now I borrowed Sony DCR-HC65 and it has ilink firewire port. I do have firewire cable, but I can't find a reliable desktop or old laptop to at least try PC express card. I finally bought Sabrent USB-AVCPT. Tape plays but I can see the quality deteriorating, a test capture was all black and white. On camcorder display it was color. I know that I need latest and greatest codecs and drivers. So I did that and I still see the same in black and white. I tried Virtualdub and VideoStudio. No luck. After some tweaking the audio messed up and out of sync. Getting worse!

These miniDVs were home videos on PAL_B, not NTSC. What options do I have? I even gave my tapes to professional conversion merchant. And even he couldn't convert them! Any help appreciated! TIA.