Hi There,

There are a few 1841 Census Records online at Freecens - Beith will go on line in about 2 months time but here are the Blairs in Beith in 1841 also Blairs in Dundonald in 1861.

Beith-1841:
Throws Blair John M 25y ag lab AYR
Barr Craigs Blair Flora F 15y female servant OUC
Gateside Blair James M 70y cotton hand loom weaver AYR
Gateside Blair Jean F 40y AYR
Gateside Blair James M 8y AYR
Gateside Blair Jean F 4y AYR
Gateside Blair Thomas M 50y dykebuilder AYR
Gateside Blair Margaret F 45y AYR
Gateside Blair James M 25y teacher AYR
Gateside Blair John M 20y wright jrnymn AYR
Gateside Blair Mary F 14y over sowster AYR
Gateside Blair Jean F 11y AYR
Gateside Blair Agnes F 15y AYR
Gateside Blair Thomas M 7y AYR
Gateside Blair Martha F 4y AYR
Head Street Blair Agnes F 75y thread winder AYR
Head Street Blair Jane F 35y thread winder AYR
Head Street Blair Hugh M 35y cotton hand loom weaver AYR
Nettlehirst Blair Jean F 40y female servant AYR
Threpwood Blair Elizabeth F 20y flax bleacher OUC
Townhead Blair Elizabeth F 30y linen clothes dyer OUC
Townhead Blair John M 2y AYR
Whitehouse Blair Jean F 25y over sewer AYR


Dundonald-1861:

Blair James 74 y Dundonald 1 17
Blair Agnes 67 y Craigie 1 17
Blair Janet 39 y Symington 1 17
Blair Mary 10 y Dundonald 1 16
Blair Bryce 78 y Dundonald 1 11
Blair Ann 73 y Dundonald 1 11
Blair Robert 64 y Dundonald 1 11
Blair Mary 60 y Kilmarnock 1 11
Blair Janet 47 y Symington 1 11
Blair James 28 y Dundonald 1 11
Blair Matthew 26 y Dundonald 1 11
Blair Agnes 24 y Dundonald 1 11
Blair Marianna 21 y Dundonald 1 11
Blair Agnes 30 y Irvine 4 3
Blair Thomas 20 y Dalry 5 9

Blair was a prominent name around Prestwick & Monkton at one time although the 1841 Census has only a few:

Monkton -1841:
monkton r station blair alexander m 30 railway collector ayr
monkton r station blair ann f 25 ayr
monkton r station blair hugh ramsay m 4 ayr
monkton village blair thomas m 30 labourer irl
monkton village blair izabell f 27 irl
monkton village blair janet f 4 irl
monkton village blair thomas m 3m irl
monkton village blair william m 25 labourer irl
monkton village blair margret f 25 irl
monkton village blair agnes f 2m irl
monkton village blair william m 45 surface man ouc
monkton village blair ann f 45 ayr
newlands farmhouse blair james m 45 ag labourer ayr


Hope this is of some help.

John Strawhorn's Book on Prestwick is worth a look.

Regards

Duncan