So as far as I can see:
1. You got a lower mark than expected and had previously been indicated.
2. You correctly went through the internal complaints procedures.
3. They didnt find in your favour, but you fel there was a cover up and a lot of inconsistencies. Presumely they probided a reasoned decision
3. You then applied to the OA and they considered your claim. They took one year and they gave you a reasoned decision.
4. You had 14 days to appeal the OA decision, but it says you waited a few months , so you chose not to (that would have been cheaper)
5. People on the internet gave you encouragement, but these are anonymous?
6. You have consulted a solcitor, they didnt give you any legal advice except they write a letter before action asking for compensation.
7. No reply to solicitors letter.
8. Sol has said it will cost £1,500 to get barristers opinion.
You will need to ask around to see if thats a typical fee. Doesnt seem unreasonable to me. Presumably the sol has someone in mind who specialisies in Uni appeals.
Its hard for anyone to say without reading the documents, reading the procedural rules and reviewing the evidence from both your Uni appeal and that of the OA. They would contain importnat info about what evidence they looked at, what their terms of reference were, how they made their decision etc. In particylar that of the OA. You should have appealed at the time.
I would have to ask myself whether a distinction was worth all the hassle or you feel you cnat let it lie.
Barristers opinion will look at all the information for you and impossible for me to say as I havent seen the documents.
Be aware legal actions are very expensive and we will be talking many thousands, especially if it ever got to trial. Only your sol can advice you based on the barristers opinion. There does look like some inconsistencies between what they indicated you might be on for, but I'd have to see the scope they have to change that between mid assessment and your final mark.
Court wouldnt be able to order a higher mark but it could award damages, not sure if it can require them to look again at their decision and remark. They would raise the fact you have already been through the complaints procedure and the OA has ruled against you.
I couldnt say what I would do for definite, just you have followed most of your appeals and the OA, but nothing has come of it. Cant really say whether you have any case and thats why you need barristers opinion. We havent seen the documents and decisions. If it was in your favour, then think again whether you have enough money to commence and pursue legal proceedings. It is v expensive. The Uni cna afford it, but can you?
It might mean you have to give up to save money or because you dont have enough.
So my view would be asking the questions above. How much do I want to know the opinion? £1,500 worth of wnat? If so and it was positive am I prepapred to finance a rial or cna I finance one and invest another potential few years to get the difference between a pass and a distinction.
Honestly I'm sceptical bout whether its worth the energy or money. You could have sat a whole new msc by the time any trial was over and you have no guarantee you would win.