I think it's strange you need to go to level 17 just to get an plus 5 level 1 item. I suggest to edite the droplist an bit:
# Ever map drop all items between the previous, current and next armore.
Example
Lv 1 can drop all lv 1-16 parts up to +5
* lv 1 parts: +1-3 (high) ; +4 (med) ; +5 (low)
* lv 16 parts: +1-3 (low) ; +4 (very low) ; +5 (unique)
Lv 6 can drop all lv 1-16 parts up to +5
* lv 1 parts: +1-3 (very high) ; +4 (high) ; +5 (med)
* lv 16 parts: +1-3 (med) ; +4 (ow) ; +5 (very low)
Lv 11 can drop all lv 1-16 parts up to +5
* lv 1 parts: +1-4 (very high) ; +5 (high)
* lv 16 parts: +1-3 (high ; +4 (med) ; +5 (low)
Lv 17 (elite) can drop all lv 1-16 parts up to +5
* lv 16 parts: +1-3 (very high) ; +4 (high ; +5 (med)
* lv 31 parts: +1-3 (med) ; +4 (low ; +5 (very low)
Lv 26 can drop all lv 1-16 parts up to +5
* lv 31 parts: +1-3 (high) ; +4 (med ; +5 (low)
* lv 46 parts: +1-3 (low) ; +4 (very low ; +5 (unique)
It's hard to create it because of the current existing maps an the level that are don't have an structure. So I suggest to ballance that again.