Winchester - Sheffield split pls

[wintonian]

Does anyone know of a decent split for Winchester to Sheffield departing on a Thur and returning on Sun?

I would like to go first class and can claim 50% of the standard fare back (so would need to excess it from STD to 1ST) and have a disabled railcard.

Edit: has to be Thur now due to a briefing Fri morning.

Edit 2:

Does anyone know what the restriction code for these is? are they restricted to boked train only like advance tickets?

 

[island]

Is it not indicated there at the top of the second page?

 

[Clip]

The following restrictions apply to services from/to London only:
Tickets are not valid for travel on: Monday to Friday services scheduled to arrive in London before 11:00, all
services scheduled to depart London St Pancras between 15:29 and 19:01.

The following restrictions apply to all services:
The Travel must be completed on the date shown on the ticket only.
Tickets can not be transferred or resold under any circumstances.
No break of journey is allowed.
Once tickets are issued, seat reservations are recommended and need to be made by 18:00 the day before travel.

 

[wintonian]

Sorry what I meant is the form seems unclear as whether you are tied to a specific train (it does ask you to input times) but the restrictions make it sound more like a super off-peak.

My thinking was if I knew the actual restriction code then I could look it up and a, make sure what is on the form is correct and b, see whether I am tied to a train or not.