The drain holes can be puttied in and sanded to match. The models are printed no less than 2mm walls so they are thick.
All models go thru a post-production process with sanding and using fillers for any defect that can be found, sometimes they can get over looked. I try to put in your hands a model that is ready to prime and paint. Color of resin and filament may vary. Anytime you want a tighter fit, the resin part can be heated up with hot water or a hair dryer and it will make it easier to take a better shape. Just don't overdo it.
Filament is a plastic substance that prints in lines and build up the 3D print. In order to fill some of the visible lines, a filler needs to be used, like wood filler or any Substitute primed and Sanded.
I have heard that Badger makes a 2 part primer that works very well and from Smooth On a product called XTC which is an epoxie overlay. This item is in the category "Toys & Hobbies\Models & Kits\Figures". The seller is "resinintheattic" and is located in this country: US. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech Republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, Korea, South, Indonesia, Taiwan, South Africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi Arabia, Ukraine, United Arab Emirates, Qatar, Kuwait, Bahrain, Croatia, Republic of, Malaysia, Brazil, Chile, Colombia, Costa Rica, Dominican Republic, Panama, Trinidad and Tobago, Guatemala, El Salvador, Honduras, Jamaica, Antigua and Barbuda, Aruba, Belize, Dominica, Grenada, Saint Kitts-Nevis, Saint Lucia, Montserrat, Turks and Caicos Islands, Barbados, Bangladesh, Bermuda, Brunei Darussalam, Bolivia, Ecuador, Egypt, French Guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman Islands, Liechtenstein, Sri Lanka, Luxembourg, Monaco, Macau, Martinique, Maldives, Nicaragua, Oman, Peru, Pakistan, Paraguay, Reunion, Vietnam, Uruguay, Russian Federation.