Ah! It's all starting to make sense now.
Time to start digging around Europe for more parts
Understandably cash flow can be an issue at times like this if you suddenly decide on extra expenditure not previously budgeted, and something like a crankshaft is very expensive and very heavy - hence 'heavy' shipping costs too. So it might be worth listing in detail all of the 'old' parts you had been intending to use, and sorting them according to:
1. can I use it for now, and replace later quite easily when I can afford it? - pushrod tubes and even the pushrods themselves come into this group. Also external parts like the distributor.
2. could I use it now if a replacement later is very difficult technically, provided the old part can be checked by experts and reconditioned in some way to be like new? - here the crankshaft is included. Maybe also the camshaft (I can't recall if that's been mentioned earlier or not).
3. this absolutely MUST be renewed, using the old part is totally out of the question regardless of how easy it might be to replace it. This group will include things like O-rings, oil seals, gaskets and of course main bearings and as has been mentioned big ends. You might also want to include small end gudgeon pins, circlips and any other spring clips, end float sprung washers (in my day I recall we used to call these 'Thackereys', never knew why), split pins and the like."
This analysis will not only act as a checklist to ensure you consider every single component of the engine, but also lead on to a bill of materials for purchase and a schedule for the order of work to be undertaken. It will also impress upon you if not already impressed just how many parts there are in even a simple engine like the 126 that make it all work !