such as + auxiliary verb
Solution 1:
It is a valid but somewhat old usage. It is used in old prose as well as in modern-day legalese. Especially the following phrase which is somewhat common in legal documents
Such as may be considered expedient/necessary
In this case, "such as" means "of the type/kind that"
So the author means
If the party is of the kind that will please one, we hope you'll receive them