Thanks to all so far. Jack, not sure if good or bad but I think the saloon cabin top on the Moorings is a different design to the 38s5.
A bit more background.
I replaced the starboard sheave (3 leech controls and mainsail halyard), frame damaged -bent- etc so luckily I was able to replace with a similar design (old stock in an old fashioned chandler) a couple of years ago but I just used 4 bolts the same size, only 2 previously, with heaps of sikaflex screwed into what ever was under the coach roof (they did tighten up real good though) as back then I couldn't work out how to get behind the liner either. So far they have held up ok and any tension is very horizontal.
Unfortunately the port side is more complicated as I have added 2 reef lines back to the cockpit (to save the aging legs having to go to the mast gooseneck's horns for reefing of the luff) and a Cunningham to the original single (sheave needs replacing anyway) mainsheet line.
My intention here is to replace all my 'dodgy' add-on blocks and single sheave with a double stack 2 sheave ball bearing Garhauer or similar. The deck is 'smooth' in this area hopefully large enough for a 2 block organiser unlike the starboard side which is smooth over a larger area e, enough to cater for the 4 block. The main tension will be taken by the original outer bolt. If the nut underneath was secured, that would be make things easier but I don't think I could be that lucky hence needing to drop the liner to replace the nut and check enough support for the 2nd bold especially as the port side has the mainsheet line, albeit again a very horizontal deflection from the blocks at the base of the mast.
In summary, no easy way out, the liner has to come down, somehow, to avoid doing any more 'dodgy' screw in bolts.