I can understand the 1
♠, since 4
♠ may work out poorly and no in-between
♠ bid makes sense. I would 100% bid 4
♠ at favourable, and would be inclined to do it here, but I do not believe that 1
♠ is awful. The fact that my second suit is
♥ plays a role, since it makes their game chances less clear.
I strongly disagree with redouble.
Bidding space is a significant issue, and with the west hand, you can forsee the need to consume space.
Also, for related reasons, I prefer to use redouble to show Hx of
♠ where H is A/K (and in some partnerships, may be Q) and some cards but not enough to make any other more descriptive/preemptive bid. This treatment greatly helps partner in leading... if you redouble, he can safely lead from a broken sequence, and if you pass, he knows to lead something else. That is worth the small additional bidding space afforded to the opps by your redouble.
A fit-showing jump, for me, shows 9+ cards in the suits, so I would not do it: and any temptation I have to stretch is reduced by the fact that North opened 1
♦.
So I fall back on whatever shows a good raise: for me, 2
♥, transfer. If unavailable, 2
♦... a cue by a passed hand must logically be based on a fit.
East should 100% bid 4
♠ on this sequence, no matter what N does.
North probably bids 3
♣ anyway, but if playing good/bad, may try 2N and over 4
♠ they may go wrong (but don't hold your breath). The odds are that competent opps will reach 5
♣. However, some imaginative North's might squeak 2
♥, hoping that partner holds 5
♥ or that the moysian plays well. Now we are in business
'one of the great markers of the advance of human kindness is the howls you will hear from the Men of God' Johann Hari
Bidding:
pass 1♦ 1♠ Dbl
Rdbl 2♣ pass 2♠! (Cue)
3♠ pass pass 4♣
pass 5♣ all pass
Lead: ♦3, 11 tricks