Try Fairclough
Fairclough Sailmakers, who now mostly make and install boat cover, made one for our Legand 37.5 earlier this year. My partner and I installed it in just over 5 hours. The entire transaction was handled by phone. They measured a sister ship to develop the pattern for our cover. They have many patterns, but not one for the 37.5. They may have a pattern for a 37 cutter. Our cover fit fairly well. Next year, we may need to take tuck here and there and maybe change the lentghs of couple of zippers, but overall its works great.Their phone is 203-787-2322 in New Haven CT. They are not cheap. Shipping is about $150 to Michigan. I do not know if they can meet your time frame. You would need to ask them.