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I had no access the to trust assets prior to distribution and dissolution of the trust."
That fact is largely irrelevant but whether or not you actually purchased the shares from the trust is relevant. In that instance, your basis would be what you paid for the shares and your holding period would begin on the purchase date.
If this happened to be an in-kind distribution of shares to a beneficiary, then the beneficiary would have a carryover basis (i.e., would use the trust's basis as his/her own basis) and the holding period would start on the date the shares were purchased by the trust (i.e., tacking is permitted).
