From an expat perspective as other posts say yes, spoilt for choice and depends on what size frameset or complete bike you need.
I am always on the lookout for a good 531 framset or complete bike. I grew up with these around Nottingham (hometown) As i'm now in Melbourne Aussie, I might as well be on Mars. Sellers are reluctant to ship downunder have heard all the reasons why not and a few that made me laugh.
I see yours going for 100 stg Westyboy, looks good for 25yrs. As you say you know its history. Be happy to give you 150 stg right now!
If I could I'd be on the next plane over buy up 20 or so 531 framsets and the same number of complete bikes, into a shipping container and make a killing here in Australia.
Our money is just as good, my ebay acct is at 100% for 239 buys I buy all over the world Poland, Hungary, US Canada and locally. No am not being smart am saying if the bike or the parts are right I buy. Am not fabulously rich either. Like you in the UK I like my road bikes.
A bike box, take the wheels and pedals off. Turn the bars 90 degrees, pack the wheels with cardboard and sticky tape around the most obvious parts wrap them in an old towel or t-shirt. Wrap the chain separately tie the brake n gear cables so they aren't loose. Wrap the frame in an old towel. Put the frame & the wheels in the box and pad the box out with folded newspaper & cardboard. Lightweight, easy to get hold of.
From experience this works, I know i have brought bikes into Australia in the 150 quid Pro Bike carriers and bike boxes as described through TNT and DHL and I paid for the shipping.
I tell you this as you see its not that hard or time consuming for guys who can strip a bike in 30 mins for a routine service.
So, its not the nightmare, end of the world stuff, its straightforward. The professional carriers do it right. Parcelforce might like our own Auspost get it wrong but when you do see an expat like me wanting to buy a good 531 or 753 or Columbus SL please don't write us off. Talk to us and we can sort something out. I can