Times Jumbo 680 Cryptic

[Four Clubs]

Can anyone help with the last two clues please.
29dn Scientist's old letter kept by British Library. 6 ltrs
-r-n-- We think it might be Brunel but cannot see why.
39ac A shock to be held firmly by this? 7 ltrs --c-u-r
Many thanks.

[sarumite]

39a Lacquer (i.e. shock = hair?)

[kettledrum]

29d Brunel

[mac44]

Brunel is correct. rune inside bl.
Lacquer, A shock of hair held by this.

[Four Clubs]

Many thanks Sarumite. Can you confirm Brunel?

[sarumite]

Yes 29d Brunel (bl = British Library) .. rune = ancient letter

[kettledrum]

Sorry! I didn't read the rest of the question
B L 'keeping' rune (ancient letter)

[Four Clubs]

Many thanks to you all.

[kettledrum]

This is as busy as the shrubbery at 9 am on a Saturday!