Well you picked a tough one for a project. Not that it's tough to work on, just that many of the parts have been long discontinued - that can lead to a lot of looking and long periods of waiting.
Depending on where you live and how prolific this motor was in your area you might easily find parts for it, otherwise you might be chucking many bucks to one of the few recyclers that might have what you are after.
On a positive note, it looks like most of the ignition (or all of it) is there. If the coils and condenser are fine that is a major plus. Unless you have removed some stuff you are obviously missing the "no longer available" flywheel plus it's nut and washer and the entire starter assembly, which in it's individual parts was a bit of a nightmare - finding one "whole" is what you should shoot for. Again, most of it is "no longer available" - so used market sources if you can find one.
Merc used two different carbs on this model. The earlier ones had a Tillotson and the latter a Walbro. Rather uncommon, but in this case, Merc still stocks a kit for the Tillotson but not the Walbro (that may or may not be an issue depending on the condition of the carb). Both carbs look the same (until you look close) so can't tell from your pics which you have.
Do you have the top cowl (cover/hood - pick your term) - if not you will need to find one of those as well.
Personally I would spend about 15 minutes on this motor. The first few minutes would be spent attempting to get a compression reading (a little tough lacking a flywheel, but would jury rig something). If the compression was ok I would contact Twin City Outboards with my list of "needs" and see if 1) they have the stuff and 2) how much they are trying to get for it (and it wouldn't be cheap - if they have the flywheel and starter assembly I would suspect they would be looking for somewhat over 300 bucks for it - generally 50% of the last list for new parts when they were still available - plus shipping of course).
If that was the case (cost that is) I would finish stripping the motor down, sell off whatever was usable and move on to something else. In running condition this motor is worth maybe a couple hundred bucks - somewhat less that what I estimate if would cost you fix it IF you can source the parts.
A 1970's/early 80's Johnson or Evinrude portable is decent project motor - they have great parts support. A 1986 or newer portable twin cylinder Merc is likewise a good project with decent parts support.
This model maybe not so much...