76 Grampian 28?
$10,900 seems like an awful lot of money for a 1976 Grampian 28 with no head. After all this is a 26 year old boat and one that was not very well regarded when she was new. early Grampians from the mid-1960''s were very nicely built but by the late 1960''s and early 1970''s Grampian had become a ''value oriented'' builder and was cutting corners that probably should not have been cut. I helped do a number of repairs to a Grampian of that era and these were not very good boats. The 28 was an effort to clean up their act and was a nice boat in many ways but still had a number of build quality issues and fairly or not, was seen as being tainted by Grampain''s earlier reputation for mediocre quality.
Beyond the generalities of the Grampian 28, you can expect to find some ''issues'' with any boat this age. Unless very well maintained and updated by a previous owner, you should expect to need to address some combination of the following items:
∑ Sails, chainplates, mast step and associated suporting structure, standing and running rigging that are well beyond their useful lifespan,
∑ an engine that is in need of rebuild or replacement,
∑ worn out or out of date deck, and galley hardware,
∑ worn out upholstery,
∑ Out of date safety gear
∑ electronics that are non operational, or in need of updating,
∑ electrical and plumbing systems that need repairs, upgrades to modern standards or replacement. The electrical system on the Grampians in particular was pretty poorly done.
∑ Blister (the late 1970''s begins the worst period for blister problems), fatigue, rudder, hull to deck joint or deck coring problems
∑ Keel bolt replacement.
∑ And perhaps a whole range of aesthetic issues.
As to your specfic question about upgrading the head with a sink and a shower, if I remember correctly Grampian 28''s have a very tight head compartment. They had a head with a sink that slid out when needed. Installing a new good quality head is not all that expensive, perhaps $200-500, a range that assumes that you only need a head and some hoses to assuming you need a holding tank, thru-hulls/seacocks, and associated pluming and you are doing the work yourself. I ma not sure about this but I sort of thing that the sink drained into the toilet if I remember correctly and because of its outboard position would need to have a check valve if you plumbed it directly into its own drain (nothing should plumb into the head discharge and you can''t plumb it into the head intake without a valving system. As to a shower, beyond the sheer tightness of the head compartment, is the issue of a sump. I don''t believe these boats have a sump. if I remember correctly, in order to gain a little more headroom you are actually walking in the bilge as you walk forward. Showers need a way to collect and discharge the grey water. On a small boat there is usually a sump that drains into the bilge (not the best way to go) or a more complicated sump with its own discharge pump which is a better set up in all ways. The sump with pump requires a bilge that is tall enough below the decks for the pump and so cuts 4 or 5 inches out of headroom. In the Grampian you would have to build this sump and the grate above it and either install, wire and plumb the sump pump and plumbing or try to plumb the water to a bilge which I don''t beleive would be very easy if I remember correctly how these boats were constructed. (Its been well over 20 years since I looked at one of these boats so you will need to study this out for yourself.)If you can drain to the bilge you can probably install a shower for $200 to $300 (glass a sump, build a grate, and add a pressure water system). If you have to do a sump and pump add a couple hundred more for the pump, switching, wiring, backflow preventer, and plumbing.