rough idle? air leak? glow plug? injectors? no fuel leaks anymore... help?

1998 e300 TD with 135k miles

Situation:
*On a cool morning, the car starts fine after normal glow
*immediately idles rough (probably 6 on a scale 1-10, definitely not normal)
*less rough when brake pressed and shifted in drive
*not too noticable while accelerating, normal driving... mixed city/ highway
*very rough again when let off accelerator approaching stop
*still rough again while braking, slowing to a stop
*not as bad at complete stop is reached (still in D, drive gear), but car will idle very rough if shifted into Park when stopped or Neutral (stopped or rolling Neutral)
*all symptoms remain the same for at least 15-20 minute commute
*less rough after 1/2 hour or more of driving, e.g a short road trip.
*car runs fine after long drive- no noticable shake, vibration or rough idle when hot or fully warmed up.
*Note, car reaches full 80c temp within 2-3 miles from home (5 min.)
*this rough idle/ vibration has been on/ off for nearly a year to varying extent
*no CEL or GP faults
*no known GP service or replacement to my knowledge (bought car @ 74k- now at 135k but no service book included)

Recently replaced:
*had a major fuel leak, replaced fuel delivery o-rings, copper washers
*also replaced plastic fuel lines at the same time (about 1k miles ago)
*recent fuel filter, air filter, oil change (unrelated, but thought I would mention.
*did NOT replace braided fuel return lines yet.


help please from e300 owners or others with similar problems
- getting more and more frustrated by the day.
Phil

__________________
Phil
Previously loved
variety, but I miss the 99 F350 PSD- 37k, traded, damn

Current stable
98 E-300 TurboDiesel, 253k
http://www.facebook.com/people/Philip-Underwood/762882374