Cutoff scores do not cross populations well. The cutoff score for a measure can be different, depending on whether the participants/clients/patients are treatment-seeking, trauma-exposed, in treatment for PTSD, from a non-clinical sample, from a primary care setting, etc. They also need to be selected to fit the use - leaning to sensitivity if the use is clinical screening when a false positive has a low cost (in dollars and anything else) and leaning to specificity when the cost is high for false negatives. In addition to that, I'd advise caution about interpretation of results based on a derived subscale that was not developed to measure a specific disorder. In one validation article on this measure (posted on ResearchGate here: https://www.researchgate.net/publication/5560605_Reliability_and_validity_of_the_SCL-90-R_PTSD_subscale), the abstract states "it should only be considered a general indicator of distress with limited use for men."
Article Reliability and validity of the SCL-90-R PTSD subscale
I am also interested in assessment of individuals who have PTSD or who have experienced various Traumatic incidents. Is their a list of current and reliable tools and their usages i.e. screening, to gauge progress, to determine impairment of functioning in ADL, relationships, and social situations, etc.