First I've heard of an "accessory port" vs. a lighter rerceptacle. Do
you know if those are available as aftermarket items which can be
installed separately from the usual lighter receptacle?

Yes. Try www.galls.com.

That's it! That's the plug I borrowed from my buddy. So he didn't get
it at a truck stop after all. I'm outta here for the neighborhood
Radio Slack!

Tnx Andy!

And a good thing about the Radio Shack website is now you can look up an item,
type in your zip code, and it'll tell you if that item is in stock in any of
your local Radio Shacks!
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73! de Andy KC2SSB
Beachwood, NJ USA! Grid FM29vw
http://vhfradiobuff.tripod.com