My double monks arrived this morning, really pleased with them and great service from Meermin, much quicker than I had anticipated based on comments in this thread.
Placed order 18 April
Paid 24 April
Shipped 26 April
Delivered 1 May
Thanks for your feedback! I think what I will do is see if I can exchange for a 38L which is not only 1" longer in the sleeves and 1.2" longer in length but also has a smaller chest and waist measurement. I am not particularly confident in my tailor's abilities so I think this would be the best option.