I just chanced upon your blog!! I'm incredibly interested in Ross's Season 3 coat, what would be a modern equivalent I could purchase for my husband? Thank you for your time!
The difficult thing about Poldark’s costumes is that there isn’t as large of a market for recreating the costumes of the series. Your best bet would be to contact one of the Etsy sellers linked here that sell Hamilton/general 18th Century designs to negotiate a custom order of a costume according to Ross’ promo pics for S3. Be prepared to spend several hundred bucks on this endeavor, these are specialty items, often custom made:
https://www.etsy.com/listing/584401081/mens-18th-century-jacket-scottish?gpla=1&gao=1&utm_campaign=shopping_us_CostumesbyAly_sfc_osa&utm_medium=cpc&utm_source=google&utm_custom1=0&utm_content=9919544&gclid=EAIaIQobChMIg4r_k6T82QIVwQOGCh1_VQ43EAQYFCABEgKLBfD_BwE
https://www.etsy.com/listing/583065345/frock-coat-adult-custom-colonial-rev-war?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=18th%20century%20mens%20coat&ref=sr_gallery-1-5
https://www.etsy.com/listing/570063264/18th-century-blue-wool-civilian-coat?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=18th%20century%20mens%20coat&ref=sr_gallery-1-2
https://www.etsy.com/listing/88618211/custom-made-18th-century-3pc-frock-coat?ga_order=most_relevant&ga_search_type=all&ga_view_type=gallery&ga_search_query=18th%20century%20mens%20coat&ref=sr_gallery-1-3
If you want something already made that’s similar to Ross’ style, I highly suggest trawling eBay using the search terms “18th Century men’s coat/18th Century men’s theatrical costume”/18th Century reenactor mens costume”. (These terms avoid the cheap Halloween listings from popping up.) This is one example of a reenactor letting go of old wares. Make sure you have notes on your husband’s measurements in inches so you can weed out too small/too big items:
https://www.ebay.com/itm/REENACTOR-18TH-C-REV-WAR-COLONIAL-MENS-COAT-WOOL-JACKET-LINED-MEDIUM-NEW-WINTER/162956232948?hash=item25f0f2c8f4:g:HGsAAOSwiBJaNCuI
ETA: These are additional ready-to-wear links. They’re not exactly like Ross’ styles but much closer than the Halloween stuff:
http://www.townsends.us/1750-1760-wool-civilian-coat-wc-149.html
http://www.townsends.us/mens-costume-civilian-coat-cc200-p-1566.html
http://www.townsends.us/mens-18th-century-civilian-coat-mc150-p-472.html
If these options are outside of your budget range, I can also investigate to see if anyone in the historical sewing groups on Facebook could work with your budget to complete the costume.
Happy shopping and please do not hesitate to message or send me another ask if you have follow-up questions!