ts1 piston grades

I've got a TS1225 motor to strip with a grade b barrel in good condition. Looking at different pistons/rods for rebuild;
asso is easy just a straight grade b to match
Ron moss has Avanti reed in 3 grades, at 69.97, 69.98 and 69.99 - this is my preference at price !
Wossner for a 116 rod from af are 69.95 no grading
Beedspeed have a reed piston for ts with no grading and just state buy the 70mm version - a possibility
Mb do grades A to d of a 70mm piston - not a consideration !
I want to buy all the rebuilt parts before strip (as far as possible) after Brid. Already have a cranks available with 107, 110 and 116. My preference is 110mm rod with a Ron moss piston (currently on special at £50). My thinking is get the Ron moss 69.97 grade a.
Any comments on the sizing minefield ?
Easiest way is to measure cylinder but I won't be stripping it til later in year as it was serviced in January (should have measured it then !).
Just thought I have a grade b asso piston that I can measure when I get home.
asso is easy just a straight grade b to match
Ron moss has Avanti reed in 3 grades, at 69.97, 69.98 and 69.99 - this is my preference at price !
Wossner for a 116 rod from af are 69.95 no grading
Beedspeed have a reed piston for ts with no grading and just state buy the 70mm version - a possibility
Mb do grades A to d of a 70mm piston - not a consideration !
I want to buy all the rebuilt parts before strip (as far as possible) after Brid. Already have a cranks available with 107, 110 and 116. My preference is 110mm rod with a Ron moss piston (currently on special at £50). My thinking is get the Ron moss 69.97 grade a.
Any comments on the sizing minefield ?
Easiest way is to measure cylinder but I won't be stripping it til later in year as it was serviced in January (should have measured it then !).
Just thought I have a grade b asso piston that I can measure when I get home.