Half of the stuff musicguard cover for (i.e. actual replacement) is covered on home insurance - that includes away from home. You just need to do a little research and speak on the phone to someone from the insurers or someone you know who works in insurance. There's always one!
Also remember that there are only 3 (or poss 4) insurance companies in the UK, as in those who acutally underwrite the policies. Even many of the huge players are brokers in reality, despite what the ads tell you. The policies are written slightly differently etc. etc. but there really is not much in it - that's why I think that all these little specialist areas of cover are a rip-off because more often than not they can be listed under a home policy for very little extra or are already included. Professional musicians excepted.
I was in a band having about £18k worth of gear insured at a lockup. Speaking to someone at musicguard when we added a load of gear at the same time as renewing the policy, I asked if we needed an alarm at that amount (it was near the threshold) and was told no. It all got nicked, 'nuff said. The slightest i not dotted will result in no payout so it was fair enough - I should've read the small print myself.
I honestly believe that the amateur musician (which most of us are) shouldn't bother getting insurance away from home (or maybe ask if your home policy will extend that - things like bicycles are anyway) because you have got to be totally nuts if you leave gear unattended at any point, ever, ever, anywhere but home as there are normally at least three of you in the band so one stays with the gear.....