Great start Scrub.
You will find that you will need to fill the layer marks that the printer leaves as it deposits the layers. It also depends on the print layer thickness you specify. I tend to use .15 or .2 mms for prototyping but change to .1 mm for the final print as it gives a much smoother finish so not so much filling and sanding. You may also find that printing a 5mm wide x 2mm thick 'rim' around the inside base of your print will add strength and assist in joining to the next component - possibly also at the top for the same reasons. where the gun ports are you are likely to have weak points as printed components fracture easily along the deposition line, so it may be worth adding vertical strengtheners, even if they are only 2 or 3mm thick they will greatly strengthen the result. If you need any advice or if I can assist in any way then please pm me.
Good luck with your new printer and have lots of fun
Carl is over egging a bit
, there are a number of Masters of 3d printing on the forum (e.g. Woz and wibblywobbly), I am relatively new to 3d design and print so very much at the steep part of the learning curve.