Rolex 3135 running mega fast

[billsbuddy2]

Some of you watch techies may shriek in horror by this post but I will give it a go! I recently bought a 16233 DateJust case and movement off ebay that was badly damaged. I replaced the parts that were required and bought a 2nd balance wheel complete without the hairspring as the one I have seemed to be OK. I fitted it to the staff making sure that the end of the hairspring stud lined up the opposite end with the roller jewel underneath. I ensured the spring was level and not touching any part of the balance wheel.
Once placed back into the reconditioned movement I noticed it gaining about 5 sec per minute! I ensured the position of the regulator (not a true regulator on Breguet hairspring) was central as possible for equal oscillation.
I then noticed that the hairspring was not centered so I reshaped the hairspring carefully to ensure that when lining up the stud to the balance bridge it slipped in without deformation (I saw this on the official Rolex video + I found good quality photos of this hairspring to give it a go. The shape was out for some reason but the hairspring was flat). I fired it back up and the gain is exactly the same. I read up about demagnetizing watches and indeed the movement especially around the balance was active on the compass. I have a demagnetizer for tape heads and read that these work fine. I did this and the compass no longer responds but guess what? No difference in speed. The movement is on a fast train. There is no point in adjusting the balance wheels weights until there is a reasonable reduction in speed or have i got this wrong?
The balance is true and seems happy in motion. It's just the excessive speed. Can anyone suggest something other then taking it to a watch maker just yet? Thanks in advance

[Ironstark]

You cannot mix and match hairsprings and balances. They are matched to one another. Think of it as a marriage where divorce is not an option!!The hairspring is vibrated to the specific balance wheel and each balance wheel will be poised. The poising will require weight removal from the balance wheel. How much will be removed will be different for each and every balance.
Tiny differences in balance mass/weight will make large differences when you attach a hairspring to a balance.
For a freesprung balance (as a 3135) there is no regulator to make large timing adjustments and without mass screws on the balance rim (as with 1530 type balances etc..), you cannot attach timing washers to add weight to slow it down.
There is nothing you or any watchmaker can do to correct this. It has nothing to do with magnetism in this case. I have seen old balances in watches that come in for service where a "watchmaker" (I use the term loosley) has glued small pieces of metal to the underside of a balance wheel to add weight but this is not advisible since there is no guarrantee it will stay there!!
Its a new balance complete.

[billsbuddy2]

Thanks for that. I bought another hairspring to see if I could slow it down further. It has but still way too fast....live and learn. Watch out for some spares on ebay!