I cracked it! I went ahead and duplicated an existing role, and trimmed off all of the guff I didn’t think my sales role would need. In the end, I ended up with;
assign_product_terms
assign_shop_coupon_terms
assign_shop_order_terms
assign_shop_webhook_terms
connections_view_public
delete_others_products
delete_others_shop_coupons
delete_others_shop_orders
delete_others_shop_webhooks
delete_private_products
delete_private_shop_coupons
delete_private_shop_orders
delete_private_shop_webhooks
delete_product
delete_product_terms
delete_products
delete_published_products
delete_published_shop_coupons
delete_published_shop_orders
delete_published_shop_webhooks
delete_shop_coupon
delete_shop_coupon_terms
delete_shop_coupons
delete_shop_order
delete_shop_order_terms
delete_shop_orders
delete_shop_webhook
delete_shop_webhook_terms
delete_shop_webhooks
edit_others_products
edit_others_shop_coupons
edit_others_shop_orders
edit_others_shop_webhooks
edit_private_products
edit_private_shop_coupons
edit_private_shop_orders
edit_private_shop_webhooks
edit_product
edit_product_terms
edit_products
edit_published_products
edit_published_shop_coupons
edit_published_shop_orders
edit_published_shop_webhooks
edit_shop_coupon
edit_shop_coupon_terms
edit_shop_coupons
edit_shop_order
edit_shop_order_terms
edit_shop_orders
edit_shop_webhook
edit_shop_webhook_terms
edit_shop_webhooks
edit_users
list_users
manage_links
manage_product_terms
manage_shop_coupon_terms
manage_shop_order_terms
manage_shop_webhook_terms
manage_woocommerce
publish_products
publish_shop_coupons
publish_shop_orders
publish_shop_webhooks
read
read_private_pages
read_private_posts
read_private_products
read_private_shop_coupons
read_private_shop_orders
read_private_shop_webhooks
read_product
read_shop_coupon
read_shop_order
read_shop_webhook
unfiltered_html
view_woocommerce_reports
And, as if by magic, this new version of the sales role can now access the dashboard, with access only to the WooCommerce, Products and Users panes.
If anybody is interested, I have been using the inspiringly named User Role Editor plugin to create and edit user roles.