All changes to tower
| Date | Change | Source |
|---|---|---|
| 9 Apr 2020 | 1-5: nominal added; 6: nominal amended | Tim Jackson via e-mail |
| 18 Jul 2013 | 1-6: frameid added; frame info added | John Baldwin via database |
| 18 Jul 2006 | Tenor nominal added (B-35c) | Nick Bowden#66 via e-mail |