Itc of ed in gst

If you are FSD or SSD and hold ED paid stock, then as per me the credit of same is already allowed to you in your last excise return filed by you, just carry forward the same balance in TRAN-1.

Yes, ITC available under section 140(3) by filing TRAN 1

Sir, If we are FSD, at time of dealer excise return, we had not paid excise duty, bcz we only pass the excise credit to our customers on the basis of manufacturer invoice, and also generating excise invoice to our customers,
My question is,
1.how to calculate the itc on excise previous return for carry forward cases?
2. We also paid CST on our interstate purchase bill, can we avail such ITC of CST? If avail where to be show trans 1.
3. Can we will be take excise credit of Remaining stock as on 31. 07.2017. e.g stock value amount rs 1500000 and all the stocks are 18%, all stock has excise duty paid invoice. calculate here ITC amount?.
4. Where It will be show in Trans 1 form 7 or 8.?

Please help me