After a week of intensive Model Building we have come up with a solution, we did not need to use python except the autoIncrement() function in pre-logic code of our final Calculate Field tool seen in the model. The simple solution was to create a new integer field and populate every record in that field with the MAX value derived from the Summary Statistics tool then use a simple expression: autoIncrement + [MAXvalueField] we then iterate the entire function for every grid block and viola we have an incrementing field starting at the highest pre-existing number. Now that we have our incrementing value we concatenate a new field with that number and our area code(found by a separate model) and we have a unique identifier for every feature in our dataset. The script looks remarkably simple for such a long model...
import arcpy
arcpy.ImportToolbox("Model Functions")
Select_Feature_Class = arcpy.GetParameterAsText(0)
if Select_Feature_Class == '
Select_Feature_Class = ""
Feature_Layer = Select_Feature_Class
I_Feature_Layer_FEATURE_ID = Feature_Layer
QueryTable_Statistics = I_Feature_Layer_FEATURE_ID
Feature_Class_w_MAX = QueryTable_Statistics
FeatureClassNewNumber__2_ = Feature_Class_w_MAX
FeatureClassNewNumber = FeatureClassNewNumber__2_
SCleanoutApppended__2_ = FeatureClassNewNumber
NULL_FEATURENUM = I_Feature_Layer_FEATURE_ID
Value = Feature_Layer
scratch_gdb = ""
arcpy.MakeFeatureLayer_management(Select_Feature_Class, Feature_Layer, "", scratch_gdb, "OBJECTID OBJECTID VISIBLE NONE;Shape Shape VISIBLE NONE;Enabled Enabled VISIBLE NONE;Location Location VISIBLE NONE;InstallContractor InstallContractor VISIBLE NONE;Condition Condition VISIBLE NONE;PrimaryImage PrimaryImage VISIBLE NONE;Size_ Size_ VISIBLE NONE;FACILITYID FACILITYID VISIBLE NONE;FEATURE_ID FEATURE_ID VISIBLE NONE;FEATURE_NUM FEATURE_NUM VISIBLE NONE;OLD_FACILITY_ID OLD_FACILITY_ID VISIBLE NONE;GPS_Date GPS_Date VISIBLE NONE;Datafile Datafile VISIBLE NONE;LifeCycleStatus LifeCycleStatus VISIBLE NONE;FACILITYIDAUTO FACILITYIDAUTO VISIBLE NONE;NewNumber NewNumber VISIBLE NONE;test test VISIBLE NONE")
arcpy.IterateFeatureSelection_mb(Feature_Layer, "FEATURE_ID
arcpy.Select_analysis(I_Feature_Layer_FEATURE_ID, NULL_FEATURENUM, "FEATURE_NUM ='0' AND FACILITYID IS NULL")
arcpy.Statistics_analysis(I_Feature_Layer_FEATURE_ID, QueryTable_Statistics, "FEATURE_NUM MAX", "FEATURE_ID")
arcpy.JoinField_management(NULL_FEATURENUM, "FEATURE_ID", QueryTable_Statistics, "FEATURE_ID", "")
arcpy.CalculateField_management(Feature_Class_w_MAX, "test", "!MAX_FEATURE_NUM!", "PYTHON", "")
arcpy.CalculateField_management(FeatureClassNewNumber__2_, "NewNumber", "autoIncrement()+ !test!", "PYTHON", "rec=0 \\ndef autoIncrement(): \\n global rec \\n pStart = 1\\n pInterval = 1 \\n if (rec == 0): \\n rec = pStart \\n else: \\n rec = rec + pInterval \\n return rec\\n")
arcpy.Append_management("")