2nd Ed Matrix Rules for 4th Ed Game, Looking for conversion advice Options

[OptimumStratego]

My group is trying to reconcile the 2nd Edition matrix rules (which, personally, we like better than 4th's Matrix ideas) with the 4th Edition basic mechanics.

Most of the conversion has gone well:
1. Removing all of the Matrix-based 4th ed skills except Computer and Hardware, and running all tests through the appropriate skill.
2. Using the Attribute + Skill 4th ed variant with the program rating as the hit limiter.

The problem we're running into is converting over difficulty standards in a way that is reasonably balanced.

Specifically, we could use advice on how to deal with the Target Number issue - varied on Security Rating in 2nd, but universally fixed at 5 in 4th Edition.

Any suggestions on how to make the numbers work for Node Rating (1-4 Blue-Green-Orange-Red) and for Security Rating (which the RAW 2nd Ed core book implies can be as high as 12) would be much appreciated.

[Jazz]

I'd really like to see what you did (or anybody comes with "I did that before" rules) because I think "some" systems didn't crash in 2.0.

There's still some old systems running around. And decks still works.

I played SR a lot with SR1 rules. I like the new matrix but I also liked the old one. And the only problem to play in 2050 with 4E rules system is the matrix. If you have a somehow 50% definitive ruleset yet, I'd like to see what you did.

[Cheops]

I've thought about this somewhat because I also much prefer the scalability of the old systems (3e in my case) compared to the new one. Something I thought about was making checks extended (target subsystem) checks with a threshold equal to the subsystem - program rating. So if you are trying to spoof a video camera on a Slave 12 system with a Spoof 4 program you'd need 8 hits before you can manipulate the camera. System rating is rolled everytime you take an action and all hits added to your security tally. Haven't quite worked out how stealth/sleaze figures into this.