RSA blind signatures in practice
The answer is correct, you don't need to unpad the message.
When/if you verify the signature, simply check that $(\text{signature})^e == \text{pad}(\text{message})$

Regarding the padding scheme, you can just use a full domain hash.

Here's how you implement a full domain hash:
$$ \mathrm{cycles} = \frac{\text{(RSA key length)}}{\text{(SHA digest length)} \times 8} + 1$$
(e.g., RSA key length = 1024bits and SHA digest length = 20bytes)
$$ \mathrm{FDH}(M) = \mathrm{SHA1}(M || 0) \mathbin\Vert \mathrm{SHA1}(M || 1) \mathbin\Vert \ldots \mathbin\Vert \mathrm{SHA1}(M || \mathrm{cycles}-1)$$

where $||$ denotes concatenation