It would be a bad idea to trust sail makers dimensions. There are too many variables and inconsistencies. Especially on a short run production boat like this. On something like a Catalina
22 where they made over 16,000 and never changed the rig that is another story but on a boat like this it would be very dicey. Even assuming they only had one rig on this boat, often sail makers can only supply is a "P" and "E" dimension that is accurate enough to give a quotation. But usually they will not have detailed information like the mast
and boom hardware
, tack pin setback, leech dimension, roach, etc. You really should measure the rig to be safe or lay out the old mainsail
and measure it under tension. I can link you to measuring instructions privately if you want to PM.