Framebuilders - derailleur hanger options

I bought a cheap MTB to cut up for a trike project. I assumed that if the trike worked well, I could upgrade the components later.

One of the parts I wanted to use was the rear dropouts. They are horizontal with no dérailleur hanger (see the bottom photo here (http://www.norcom2000.com/users/dcimper/assorted/inanities/recumbent/trike/trike_01/trike_01.html)).

The OEM wheel is a 5-speed. If this trike works really well, I'd want to put a Shimano 8- or 9-speed wheel and a better dérailleur on it. What options do I have as far as getting a normal hanger on there? Does anyplace make a hanger that bolts-on the same but that supports current stuff? Or does Shimano still make 9-speed dérailleurs like this?.......
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if your gonna be cutting it up, why not just order some new rear drops that fit your need and replace the one's on there?

if your gonna be cutting it up, why not just order some new rear drops that fit your need and replace the one's on there?
Well, these ones came on the bike. I can't use the OEM derailler if there's an integral mount in the way.

And yes I could have bought everything separately, but that would have cost more than I spent for the bike as it is....

Is it cheaper to buy different dropouts, or is it cheaper to buy an adapter for newer dérailleurs?.... If someone has an old frame and wants to mount a newer drivetrain on it, what do they do?
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I can't remember the bike, but I saw one reccently with Pauls horizontal track DOs, and a deraileur mount was brazed on. It was just like a rack eyelet, except bigger. In the old days we used separate brackets that normally bolted through the drop, which are seen on many cheaper bikes these days. But in the old days the forest of braze-ons we get for free these days was pretty rare Most bikes had stuff banded or bolted on.