Errr, first thing if you don't have a logbook DON'T dismantle it . DVLA may well require a verification letter from an Owners club on their V765 list to confirm its originality and then want it taken to them for the,m to confirm the letter tallies with teh vehicle.
There is an 8 points system if you want to avoid issues with the logbok later and to remain legal forever.
Details here :
http://www.the-ace.org.uk/chassis-and-monocoque-modification/It's perfectly feasable to build a modified Devon under the rules as I've done it myslef , using Rover V8 and auto, Mk 2 Jag (solid) axle on original leaf springs , retaining original steering assembly and adding MGB discs ( very slight machining of MGB upright to make it fit ).
It was striped when i got it,

and whats worse is its been off the road apparently since 1971. Now some time around 1975-1980 Swansea decided that you had to say if you still had the car or not or it was presumed scraped,and they got to sell your reg number in latter years

i obviously don't know if this cars owner at that time bothered to tell Swansea, could that be a problem?.
On a positive note it is a genuine thing all the plates are there the one on the front o/s chassis leg and one on the body side near the n/s bonnet hinge, both are readable. The Engine and gearbox are long gone. What is my first move then with regards the log book, i can get it to Beverley or Sheffield if need be, But should i just apply for a log book first see what happens, my mate got an Anglia log book straight off, but it had only been off the road since the mid 80s.
MGB front brakes i got a front hub set up off a MGB with this car . talk me through it thoroughly please, parts are similar but not the same.
like this when i got it last week.

Now what!
i got the MGB brakes and the originals with the car.

Now what!
Although it is true about the loss of the logbook they would still be able to issue A number as opposed to THE number. Still requires the support of a club on the V765 list. I'm presuming you have the buff log book ( RF or VE 60 )? Best bet is pop in your local office and they'll guide you through it. Missing engine may be an issue though

.
To fit the MGB kingpins you have to machine the bottom section to match the original Devon piece and then machine the inner bush so it is 0.005" oversize to the bottom kingpin which allows it to rotate . I seem to remember I messed with a spacer plate under the top shocker to realign the caster angle . It was 23 years ago so parts are a bit hazy without the components in my hand.