I recon ya mad.
Keep the old girl I recon.
Its simple,buy an old crappa to drive for a few months, get the better 151 kw donk out of a 100 series write off complete car, fill a garden shed with spares from it and sell the rest, fit the interior of yours with better furniture (GXL gear fits real easy, happy to show you). Sell ya running turboed 1HZ.
Fit all the go faster gear into your 105 from the 100. almost 50% more power.
Get the 105 on the road.
Sell the crappa.
Sorted, yep, it took some time, but, look at the shed time you just scored.....
You can thank me later.