After market hard pannier/top box kit for Sportster?

That is the longer term plan...then leave the bike nice and clean of all the luggage, tow the trailer to the destination, with all the kit and then have the bike empty for local touring.

I have the 1200 cc kit, but still have not got around to putting that on yet, and have started looking up various trailer hitch designs. I have seen 2 companies that do drawbars for the Sporty, but that is all for another day.

I think Saddlemen sells a quick detachable mount.
They have one for hard bags. They sell one simular, it has the braces to keep soft bags off your wheels.
In my old catalogs they are around $60, probably not over $100 now.
They mounts have a bolts the replaces your fender mount bolts. This bolt has a special head where the mount hooks to the bike. Align the holes and they snap on and you can lock them on.
Unlocked the just snap off and you can take them with you. I think you can even get carry straps that hook in the mount holes so you can carry them like suitcases.

That sounds just great, I'll google the name and see what appears.

have just had two separate unexpected bills for £1500 ($2250) extra Tax and repairs to apartment block. There goes my fund for upgrading the bike

I did some checking in my old catalogs. The Dennis Kirk is a 2004. It list the Saddlemen kit as part #50-5105 fit Sportster up to 03.
In my J&P catalog 2007. It don't list the Saddlemen kit. It has an Easy Brackets #840-006 Sportster 94-03, #840-190 wide bracket - # 840-191 slim bracket, 04 -07 Sportster.
The Ghost brackets, #840-029 for 94-03, #840-088 for 04-07.
They also list the carry straps.