Andy
I am glad you noticed the gap under the front rail. I went for the obligatory ‘sit in your Roadster’ picture

and the legs on the sh**y plastic A frame spread and I nearly ended on the floor,

also when we had all the wet weather the board wasn’t supported properly so as you said it has now got a gentle curve on it.

On a positive note, although it has now warped the chassis (as you can see) has remained straight.
Ginge