Using TA Crank arms w/ Viscount BB?

It's fair to say that Lambert's original parts designers/engineers were 'inspired' by the TA cranks when they created their own

If you have the early Viscount BB spindle with 3 machined grooves in then crank choice is limited. Only Viscount's own cranks fit really well on these spindles because the taper on them is like, well, nothing else out there (poor machining complicated matters too...). I think I've previously described it as a kind of mongrel ISO taper. Viscount punched in a very specific shape into their cranks which was not a bad fit with their own 3 ring BB spindle. But everything else?

The problem now of course is, what do we fit 40 years later? I've tried a variety of cranks on the 3 ring Viscount BB spindle. You can get them on okay but the challenge is making the crank sit square on the spindle. This of course matters as if it is out too much the front derailleur rubs on the inner face of the crank when you are in 10th gear - a very obvious chainwheel wobble can be seen when the crank arms are spun round.

Unfortunately, I've tried TA cranks but could not get them to seat well on the 3 ring Viscount BB spindle. The only cranks that I have had fairly good results with were these made by the likes of SR and Sugino back in the 1970s:
(Note the helpful absense of any crank offset to throw the chainline out).

velobase.com/CompImages/Crankset/165D91BA-D1BD-411F-9FA6-6CE6722692B1.jpeg
www.ebay.co.uk/itm/SR-APEX-CRANKSET-ALLOY-170-MM-DOUBLE-40-52-/151680518091?_trksid=p2141725.m3641.l6368
ratrodbikes.com/forum/index.php?threads/sugino-maxy-crankset.79663/
www.mytenspeeds.com/My_TenSpeeds_1/Feature_Bicycles/Feature_Bicycles_Canada/Velo_Sport_Criterium/Velo_Sport_Criterium_3_Shimano600Components.htm

The 'only' issue with cranks like the above is getting them square on the Viscount 3 ring BB spindle. I've found if you tap them on with a mallet perfectly square to the crank as far as you can they will go on pretty well and 'seat' pretty square with the crank when the fixing bolt is tightened in anger (well, some of the time at least). If you can, it really is best to stick with the Viscount cranks on the 3 ring BB spindle. If not, be careful and you should get a reasonable fit with cranks like those referenced above (even a muppet like me has had some success!).

Later Aerospace bikes have a 2 ring BB spindle. This is the one to have! The standard of machining is very good and the taper is - hooray - a JIS type. This hugely increases the choice of cranks that can be fitted (like the ones referenced above for example) and, they are easy to fit.

Whatever you do, don't sell your VA Pro - those things are priceless!!!