That is going to be huge ask, these sort of things usually have a 6-12 month timeframe applied to get from zero to implementation. Given we have no one on board at the moment that has the skills or knowledge of the Deed we are working under, the selection and organisation of staff and the reorganisation (including any Constitutional changes necessary) will more than likely exceed your 90 day timeframe by a long shot.
Notwithstanding that, there should be appropriate steps implemented with a report back to the members about progress (not specifically to committee or executive) every month via the magazine, per a dedicated schedule of targets (Gann chart). As long as progress is seen to be happening with this over a period of time with the achievement of all targets then the committee would be seen to be achieving adequate performance.
Yes, it will cost money to get it right, but we have seen what happens when things are left to deteriorate....it ultimately costs lives, whether by not getting sufficient report backs from incidents or simple stuff ups like the current registrations fiasco regarding gross weights.
This NEEDS to be put right once and for all, economising now will lead to similar issues occurring again.