Hull dimensions.

Hi all, I'm new to the class and this forum and in need of some info if anyone can help.

I a repairing/refitting an old hull, number 2140.

Firstly, The mast hog was not original and very rotten so I've made a new one, my problem is knowing how thick it should be. I've gone at 50mm as a ball park size initially and can't find this data anywhere, or even decent pictures of others.

Secondly, the data I can find for the mast step position gives a figure I can't even get because the bulkhead is too far aft?

Anyone else come across this?

Thanks in advance for any help.

Best regards

Carl