3 very sad 5.4's...and one very happy one!
I recently bought a 1994 Searider 5.4 that has been garaged its entire life and only has 50 hours on the engine!
It's pretty much perfect in every way.
It's a completely different prospect to the 3 sad examples of about the same vintage.
The sad truth is that once you have got a new tube sent out from the UK, stripped the donor boat back to glass/sound gelcoat, carry out all the repairs, repaint, re-tube, new engine/electrics/seat...it costs just about the same as a new RIB.
I've restored an old 5.4 and kept a close record of the cost.
True, you may have a better boat at the end of it.
My $0.02 on engines and 5.4's
It's hard to beat a Yamaha 85/90 2 stroke but if you are not in a hurry the Yamaha 50/60 four stroke is perfect and WAY more ecconomical.